{"id":40201,"date":"2023-11-27T13:50:13","date_gmt":"2023-11-27T05:50:13","guid":{"rendered":"https:\/\/autoolstore.com\/?post_type=product&#038;p=40201"},"modified":"2026-09-20T08:31:44","modified_gmt":"2026-09-20T16:31:44","slug":"autool-as503-engine-oil-tester","status":"publish","type":"product","link":"https:\/\/autoolstore.com\/product\/autool-as503-engine-oil-tester\/","title":{"rendered":"AUTOOL AS503 Optical Engine Oil Quality Tester"},"content":{"rendered":"\n\n\r\n<div class=\"autool-page-shell\"><main class=\"autool-description autool-product-page\" data-autool-lightbox=\"off\" data-autool-mobile-nav=\"false\" data-autool-rail-controls=\"true\" id=\"as503-product-page\"><section class=\"autool-section autool-product-hero autool-section--overview\" data-autool-nav=\"Overview\" data-autool-surface=\"dark\" id=\"autool-overview\"><div class=\"autool-layout-container autool-product-hero__grid\">\r\n<div class=\"autool-product-hero__copy\">\r\n<p class=\"autool-product-hero__eyebrow\">AUTOOL AS503 \u00b7 Engine Oil Tester with Transmittance Readout<\/p>\r\n<h2 class=\"autool-product-hero__title\">Screen Engine Oil with Temperature Context<\/h2>\r\n<p class=\"autool-product-hero__lead\">Use AS503 to screen engine-oil transmittance and temperature during maintenance. Separate gasoline and diesel modes, an 800 mm PTFE probe, and combined status prompts support quick comparisons under consistent sampling conditions.<\/p>\r\n<ul aria-label=\"AS503 key benefits\" class=\"autool-product-hero__capabilities\">\r\n<li>Optical Oil-Transmittance Screen<\/li>\r\n<li>Gasoline And Diesel Modes<\/li>\r\n<li>800 mm PTFE Probe<\/li>\r\n<li>Oil Temperature Context<\/li>\r\n<li>2.8-Inch Backlit Display<\/li>\r\n<\/ul>\r\n<nav aria-label=\"AS503 sections\" class=\"autool-product-hero__actions\"><a class=\"autool-product-button autool-product-button--primary\" href=\"#autool-features\">Explore Features<\/a><a class=\"autool-product-button\" href=\"#autool-use\">View Workflow<\/a><a class=\"autool-product-button\" href=\"#autool-comparison\">Specs &amp; Compare<\/a><\/nav>\r\n<\/div>\r\n<figure class=\"autool-product-hero__media\"><img alt=\"AUTOOL AS503 engine oil quality tester main product image with key functions\" decoding=\"async\" fetchpriority=\"high\" loading=\"eager\" src=\"https:\/\/autoolstore.com\/wp-content\/uploads\/2025\/10\/e0358359-7557-4500-a69a-077ad11ea559.png\"\/><\/figure>\r\n<\/div><\/section><aside aria-label=\"AS503 at a glance\" class=\"autool-product-metrics\"><div class=\"autool-product-metrics__inner\">\n<div class=\"autool-product-metric\"><strong>2<\/strong><span>Oil Modes<\/span><\/div>\n<div class=\"autool-product-metric\"><strong>800 mm<\/strong><span>PTFE Probe<\/span><\/div>\n<div class=\"autool-product-metric\"><strong>2.8 in<\/strong><span>Backlit Display<\/span><\/div>\n<div class=\"autool-product-metric\"><strong>4 \u00d7 AAA<\/strong><span>Battery Power<\/span><\/div>\n<\/div><\/aside><section class=\"autool-section autool-product-section--soft autool-section--value\" data-autool-surface=\"base\" id=\"autool-features\"><div class=\"autool-layout-container\">\r\n<header class=\"autool-section-head\"><p class=\"autool-subhead\">Key Features<\/p>\r\n<h2 class=\"autool-title\">Optical Engine Oil Reading with Gasoline and Diesel Modes<\/h2><\/header><div class=\"autool-product-grid autool-product-grid--3 autool-product-rail\" data-autool-rail=\"features\">\r\n<article class=\"autool-product-card\"><h3>High-Precision Optical Probe<\/h3>\r\n<p>The integrated photoelectric transceiver sensor detects engine oil transmittance to help evaluate oil contamination and impurity level.<\/p><\/article><article class=\"autool-product-card\"><h3>800mm Flexible PTFE Hose<\/h3>\r\n<p>The 800mm hose probe makes sampling easier around the engine bay. PTFE material resists oil, oxidation, and corrosion for longer service life.<\/p><\/article><article class=\"autool-product-card\"><h3>Gasoline And Diesel Modes<\/h3>\r\n<p>Separate gasoline and diesel engine oil modes help users check different lubricant oil standards more accurately.<\/p><\/article><article class=\"autool-product-card\"><h3>Oil Temperature Measurement<\/h3>\r\n<p>The built-in temperature sensor displays the actual oil temperature and supports \u00b0C \/ \u00b0F switching for easier reading.<\/p><\/article><article class=\"autool-product-card\"><h3>2.8-Inch Backlit LCD<\/h3>\r\n<p>The backlit 2.8-inch screen shows battery level, selected engine type, transmittance, oil temperature, and result symbols clearly.<\/p><\/article><article class=\"autool-product-card\"><h3>Sound Alarm And Result Reminder<\/h3>\r\n<p>The tester uses screen icons and sound reminders to help users decide whether the oil is acceptable, needs attention, or should be replaced.<\/p><\/article><article class=\"autool-product-card\"><h3>Silicone Handheld Grip<\/h3>\r\n<p>The silicone grip supports single-handed operation when checking engine oil.<\/p><\/article><article class=\"autool-product-card\"><h3>Battery-Powered Tester<\/h3>\r\n<p>The 175 \u00d7 72 \u00d7 29mm tester operates on 6V from four 1.5V batteries.<\/p><\/article><article class=\"autool-product-card\"><h3>Engine Oil Transmittance<\/h3>\r\n<p>AS503 measures engine oil transmittance in gasoline and diesel modes to support oil condition checks.<\/p><\/article><article class=\"autool-product-card\"><h3>Optical Probe Reading<\/h3>\r\n<p>The probe reads light transmission through engine oil and reflects contamination or suspended particles that affect transparency.<\/p><\/article>\r\n<article class=\"autool-product-card\"><h3>3 Years Warranty Support<\/h3><p>Main unit: 3-year warranty. Standard accessories: 1-year warranty. <a href=\"https:\/\/autoolstore.com\/warranty-policy\/\" rel=\"noopener\" target=\"_blank\">Warranty Policy<\/a>.<\/p><\/article><\/div>\r\n<\/div><\/section><section class=\"autool-section autool-section--workflow autool-section--workflow-anchor\" data-autool-surface=\"dark\" id=\"autool-use\"><div class=\"autool-layout-container\">\r\n<header class=\"autool-section-head\"><p class=\"autool-subhead\">Service Workflow<\/p>\r\n<h2 class=\"autool-title\">Select the Engine Mode and Sample Correctly<\/h2><\/header><div class=\"autool-workflow\" data-autool-workflow=\"\" data-workflow-mode=\"panels\">\r\n<div aria-label=\"as503 workflow\" class=\"autool-workflow__tabs\" data-workflow-tabs=\"\" role=\"tablist\">\r\n<button aria-controls=\"as503-panel-0\" aria-selected=\"true\" class=\"autool-workflow__tab\" data-workflow-step=\"0\" id=\"as503-tab-0\" role=\"tab\" tabindex=\"0\" type=\"button\">01<br\/><wbr\/>Wipe<wbr\/> The<wbr\/> Probe<\/button><button aria-controls=\"as503-panel-1\" aria-selected=\"false\" class=\"autool-workflow__tab\" data-workflow-step=\"1\" id=\"as503-tab-1\" role=\"tab\" tabindex=\"-1\" type=\"button\">02<br\/><wbr\/>Remove<wbr\/> The<wbr\/> Dipstick<\/button><button aria-controls=\"as503-panel-2\" aria-selected=\"false\" class=\"autool-workflow__tab\" data-workflow-step=\"2\" id=\"as503-tab-2\" role=\"tab\" tabindex=\"-1\" type=\"button\">03<br\/><wbr\/>Select<wbr\/> Engine<wbr\/> Type<\/button><button aria-controls=\"as503-panel-3\" aria-selected=\"false\" class=\"autool-workflow__tab\" data-workflow-step=\"3\" id=\"as503-tab-3\" role=\"tab\" tabindex=\"-1\" type=\"button\">04<br\/><wbr\/>Submerge<wbr\/> The<wbr\/> Probe<\/button><button aria-controls=\"as503-panel-4\" aria-selected=\"false\" class=\"autool-workflow__tab\" data-workflow-step=\"4\" id=\"as503-tab-4\" role=\"tab\" tabindex=\"-1\" type=\"button\">05<br\/><wbr\/>Start<wbr\/> The<wbr\/> Test<\/button><button aria-controls=\"as503-panel-5\" aria-selected=\"false\" class=\"autool-workflow__tab\" data-workflow-step=\"5\" id=\"as503-tab-5\" role=\"tab\" tabindex=\"-1\" type=\"button\">06<br\/><wbr\/>Read<wbr\/> The<wbr\/> Result<\/button><button aria-controls=\"as503-panel-6\" aria-selected=\"false\" class=\"autool-workflow__tab\" data-workflow-step=\"6\" id=\"as503-tab-6\" role=\"tab\" tabindex=\"-1\" type=\"button\">07<br\/><wbr\/>Probe-Based<wbr\/> Oil<wbr\/> Check<\/button>\r\n<\/div>\r\n<div class=\"autool-workflow__position\">\r\n<span class=\"autool-workflow__position-label\">Step progress<\/span><span class=\"autool-workflow__progress\"><span class=\"autool-workflow__progress-bar\" data-workflow-progress=\"\"><\/span><\/span><span class=\"autool-workflow__position-count\" data-workflow-count=\"\">1 \/ 7<\/span>\r\n<\/div>\r\n<div class=\"autool-workflow__content\">\r\n<div class=\"autool-workflow__main\">\r\n<div class=\"autool-workflow__panels\">\r\n<article aria-labelledby=\"as503-tab-0\" class=\"autool-workflow__panel\" data-workflow-panel=\"\" id=\"as503-panel-0\" role=\"tabpanel\" tabindex=\"0\"><div class=\"autool-workflow__number\">01<\/div>\r\n<h3 class=\"autool-workflow__title\">Wipe The Probe<\/h3>\r\n<p class=\"autool-workflow__description\">Wipe the test probe clean before use to reduce residue interference.<\/p><\/article><article aria-labelledby=\"as503-tab-1\" class=\"autool-workflow__panel\" data-workflow-panel=\"\" hidden=\"\" id=\"as503-panel-1\" role=\"tabpanel\" tabindex=\"0\"><div class=\"autool-workflow__number\">02<\/div>\r\n<h3 class=\"autool-workflow__title\">Remove The Dipstick<\/h3>\r\n<p class=\"autool-workflow__description\">Remove the engine oil dipstick or access the engine oil testing point according to vehicle service requirements.<\/p><\/article><article aria-labelledby=\"as503-tab-2\" class=\"autool-workflow__panel\" data-workflow-panel=\"\" hidden=\"\" id=\"as503-panel-2\" role=\"tabpanel\" tabindex=\"0\"><div class=\"autool-workflow__number\">03<\/div>\r\n<h3 class=\"autool-workflow__title\">Select Engine Type<\/h3>\r\n<p class=\"autool-workflow__description\">Press the engine type selection button to choose gasoline or diesel engine oil mode.<\/p><\/article><article aria-labelledby=\"as503-tab-3\" class=\"autool-workflow__panel\" data-workflow-panel=\"\" hidden=\"\" id=\"as503-panel-3\" role=\"tabpanel\" tabindex=\"0\"><div class=\"autool-workflow__number\">04<\/div>\r\n<h3 class=\"autool-workflow__title\">Submerge The Probe<\/h3>\r\n<p class=\"autool-workflow__description\">Place the testing probe into the engine oil and make sure the sensing area is properly submerged.<\/p><\/article><article aria-labelledby=\"as503-tab-4\" class=\"autool-workflow__panel\" data-workflow-panel=\"\" hidden=\"\" id=\"as503-panel-4\" role=\"tabpanel\" tabindex=\"0\"><div class=\"autool-workflow__number\">05<\/div>\r\n<h3 class=\"autool-workflow__title\">Start The Test<\/h3>\r\n<p class=\"autool-workflow__description\">Press the test button and allow the tester to complete the reading process.<\/p><\/article><article aria-labelledby=\"as503-tab-5\" class=\"autool-workflow__panel\" data-workflow-panel=\"\" hidden=\"\" id=\"as503-panel-5\" role=\"tabpanel\" tabindex=\"0\"><div class=\"autool-workflow__number\">06<\/div>\r\n<h3 class=\"autool-workflow__title\">Read The Result<\/h3>\r\n<p class=\"autool-workflow__description\">The display shows the transmittance percentage, result symbol, and current oil temperature.<\/p><\/article><article aria-labelledby=\"as503-tab-6\" class=\"autool-workflow__panel\" data-workflow-panel=\"\" hidden=\"\" id=\"as503-panel-6\" role=\"tabpanel\" tabindex=\"0\"><div class=\"autool-workflow__number\">07<\/div>\r\n<h3 class=\"autool-workflow__title\">Probe-Based Oil Check<\/h3>\r\n<p class=\"autool-workflow__description\">Clean the probe, select gasoline or diesel mode, then immerse the probe in the oil and start the test. Read the transmittance and temperature on the display.<\/p><\/article>\r\n<\/div>\r\n<div class=\"autool-workflow__actions\">\r\n<button class=\"autool-workflow__button\" data-workflow-prev=\"\" disabled=\"\" type=\"button\">\u2190 Previous<\/button><button class=\"autool-workflow__button autool-workflow__button--next\" data-workflow-next=\"\" type=\"button\">Next step \u2192<\/button>\r\n<\/div>\r\n<\/div>\r\n<aside class=\"autool-workflow__safety\" data-workflow-safety=\"\"><h3 class=\"autool-workflow__safety-title\">Before You Start<\/h3>\r\n<ul class=\"autool-workflow__safety-list\">\r\n<li>AS503 is intended for gasoline and diesel engine lubricating oil. It is not a brake fluid, transmission fluid, or power steering fluid tester.<\/li>\r\n<li>Because AS503 uses an optical detection probe, it is not suitable for engine oils containing molybdenum disulfide (MoS\u2082), organic molybdenum, graphene, or similar additives.<\/li>\r\n<\/ul><\/aside>\r\n<\/div>\r\n<\/div>\r\n<\/div><\/section><section class=\"autool-section autool-product-section--soft\" data-autool-surface=\"base\" id=\"autool-safety\"><div class=\"autool-layout-container\">\r\n<header class=\"autool-section-head\"><p class=\"autool-subhead\">Safe Use<\/p>\r\n<h2 class=\"autool-title\">Treat the Score as a Screening Result<\/h2><\/header><div class=\"autool-product-grid autool-product-grid--3 autool-product-rail\" data-autool-rail=\"safety\">\r\n<article class=\"autool-product-card\"><h3>Engine Oil Only<\/h3>\r\n<p>AS503 is intended for gasoline and diesel engine lubricating oil. It is not a brake fluid, transmission fluid, or power steering fluid tester.<\/p><\/article><article class=\"autool-product-card\"><h3>Optical Detection Limit<\/h3>\r\n<p>Because AS503 uses an optical detection probe, it is not suitable for engine oils containing molybdenum disulfide (MoS\u2082), organic molybdenum, graphene, or similar additives.<\/p><\/article><article class=\"autool-product-card\"><h3>Suzuki J20A Not Supported<\/h3>\r\n<p>AS503 does not support the Suzuki J20A engine. Contact AUTOOL Store before ordering if this engine is your intended application.<\/p><\/article><article class=\"autool-product-card\"><h3>Check Oil Additives<\/h3>\r\n<p>Do not use AS503 with oils containing molybdenum disulfide, organic molybdenum or graphene additives.<\/p><\/article><article class=\"autool-product-card\"><h3>Recommended Check Interval<\/h3>\r\n<p>Use AS503 as a reference check every 5,000-10,000 km, depending on engine condition, oil type, driving environment, and maintenance schedule.<\/p><\/article><article class=\"autool-product-card\"><h3>Interpret Engine Oil Transmittance in Context<\/h3>\r\n<p>Select only a listed fluid and use a clean, representative sample. The condition score is the tester&#8217;s screening output, not a direct measurement of viscosity, wear metal, contamination species or remaining service life.<\/p><\/article>\r\n<\/div>\r\n<\/div><\/section><section class=\"autool-section autool-comparison\" data-autool-nav=\"Spec&amp;Comparison\" data-autool-surface=\"dark\" id=\"autool-comparison\"><div class=\"autool-layout-container\">\r\n<header class=\"autool-section-head\"><p class=\"autool-subhead\">Model Comparison<\/p>\r\n<h2 class=\"autool-title\">Choose the Right Fluid Test Method<\/h2><\/header><div class=\"autool-model-compare\" data-autool-model-compare=\"\" data-current-model=\"as503\">\r\n<button aria-controls=\"compare-source-10-compare-model-picker\" aria-expanded=\"false\" aria-label=\"Open model comparison selector\" class=\"autool-model-compare__mobile-trigger\" data-compare-picker-open=\"\" type=\"button\"><span class=\"autool-model-compare__mobile-trigger-copy\"><strong>Compare models<\/strong><span data-compare-mobile-summary=\"\">Selected: AS503<\/span><\/span><span class=\"autool-model-compare__mobile-trigger-count\" data-compare-mobile-count=\"\">1<\/span><\/button>\r\n<button aria-label=\"Close model selector\" class=\"autool-model-compare__scrim\" data-compare-picker-close=\"\" tabindex=\"-1\" type=\"button\"><\/button>\r\n<div aria-labelledby=\"compare-source-10-compare-picker-title\" class=\"autool-model-compare__selector\" id=\"compare-source-10-compare-model-picker\" role=\"group\">\r\n<div class=\"autool-model-compare__selector-head\">\r\n<div class=\"autool-model-compare__selector-copy\">\r\n<h3 class=\"autool-model-compare__legend\" id=\"compare-source-10-compare-picker-title\">Model Guide<\/h3>\r\n<p class=\"autool-model-compare__instruction\">Choose one or more models. AS503 is selected by default.<\/p>\r\n<\/div>\r\n<div class=\"autool-model-compare__selector-tools\">\r\n<div class=\"autool-model-compare__count\" data-compare-count=\"\">1 model selected<\/div>\r\n<button aria-label=\"Close model selector\" class=\"autool-model-compare__picker-close\" data-compare-picker-close=\"\" type=\"button\">\u00d7<\/button>\r\n<\/div>\r\n<\/div>\r\n<div aria-label=\"Models available for comparison\" class=\"autool-model-compare__grid\" role=\"list\">\r\n<label class=\"autool-model-option\" data-model-card=\"as501\" role=\"listitem\"><input data-model-checkbox=\"\" type=\"checkbox\" value=\"as501\"\/><span class=\"autool-model-option__copy\"><strong class=\"autool-model-option__model\">AS501 Brake Fluid Tester<\/strong><span class=\"autool-model-option__tier\">Brake-fluid moisture \/ 1.8-inch \/ 6 modes<\/span><\/span><\/label><label class=\"autool-model-option\" data-model-card=\"as502\" role=\"listitem\"><input data-model-checkbox=\"\" type=\"checkbox\" value=\"as502\"\/><span class=\"autool-model-option__copy\"><strong class=\"autool-model-option__model\">AS502 Brake Fluid Tester<\/strong><span class=\"autool-model-option__tier\">Brake-fluid moisture \/ 2.8-inch \/ Expert mode<\/span><\/span><\/label><label class=\"autool-model-option autool-is-selected\" data-model-card=\"as503\" role=\"listitem\"><input checked=\"\" data-model-checkbox=\"\" type=\"checkbox\" value=\"as503\"\/><span class=\"autool-model-option__copy\"><strong class=\"autool-model-option__model\">AS503 Engine Oil Quality Tester<\/strong><span class=\"autool-model-option__tier\">Engine-oil transmittance \/ 0\u201385 \u00b0C \/ 80 cm probe<\/span><\/span><span class=\"autool-model-option__current\">Current model<\/span><\/label><label class=\"autool-model-option\" data-model-card=\"as505\" role=\"listitem\"><input data-model-checkbox=\"\" type=\"checkbox\" value=\"as505\"\/><span class=\"autool-model-option__copy\"><strong class=\"autool-model-option__model\">AS505 Transmission Fluid Tester<\/strong><span class=\"autool-model-option__tier\">ATF transmittance \/ 0\u201385 \u00b0C \/ 80 cm probe<\/span><\/span><\/label><label class=\"autool-model-option\" data-model-card=\"as506\" role=\"listitem\"><input data-model-checkbox=\"\" type=\"checkbox\" value=\"as506\"\/><span class=\"autool-model-option__copy\"><strong class=\"autool-model-option__model\">AS506 Brake Fluid Boiling Point Tester<\/strong><span class=\"autool-model-option__tier\">Brake-fluid boiling point \/ 0\u2013320 \u00b0C \/ 16 s<\/span><\/span><\/label><label class=\"autool-model-option\" data-model-card=\"as507\" role=\"listitem\"><input data-model-checkbox=\"\" type=\"checkbox\" value=\"as507\"\/><span class=\"autool-model-option__copy\"><strong class=\"autool-model-option__model\">AS507 Power Steering Fluid Tester<\/strong><span class=\"autool-model-option__tier\">Steering-fluid transmittance \/ 0\u201385 \u00b0C \/ 80 cm test cable<\/span><\/span><\/label><label class=\"autool-model-option\" data-model-card=\"as509\" role=\"listitem\"><input data-model-checkbox=\"\" type=\"checkbox\" value=\"as509\"\/><span class=\"autool-model-option__copy\"><strong class=\"autool-model-option__model\">AS509 Coolant Boiling Point Tester<\/strong><span class=\"autool-model-option__tier\">Coolant boiling point \/ 23 brands \/ 20\u201340 s<\/span><\/span><\/label>\r\n<\/div>\r\n<div class=\"autool-model-compare__selection-bar\">\r\n<p aria-live=\"polite\" class=\"autool-model-compare__status\" data-compare-status=\"\" id=\"compare-source-10-compare-result-status\" role=\"status\">AUTOOL AS503 Engine Oil Quality Tester is selected. Choose another model for a side-by-side comparison.<\/p>\r\n<div class=\"autool-model-compare__selection-actions\">\r\n<button class=\"autool-model-compare__clear\" data-compare-clear=\"\" disabled=\"\" type=\"button\">Reset selection<\/button><button class=\"autool-model-compare__done\" data-compare-picker-close=\"\" type=\"button\">Done<\/button>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<div class=\"autool-model-compare__result\" data-compare-result=\"\">\r\n<div class=\"autool-model-compare__result-toolbar\">\r\n<h3 class=\"autool-model-compare__result-title\" data-compare-title=\"\" id=\"compare-source-10-compare-result-title\">AS503 comparison<\/h3>\r\n<label aria-disabled=\"true\" class=\"autool-model-compare__difference-toggle\" data-differences-label=\"\"><input data-differences-only=\"\" disabled=\"\" type=\"checkbox\"\/> Show differences only<\/label>\r\n<\/div>\r\n<div data-compare-table=\"\">\r\n<div class=\"autool-compare-matrix__empty\" hidden=\"\">No model is selected. Choose a model to compare.<\/div>\r\n<div aria-describedby=\"compare-source-10-compare-result-status\" aria-labelledby=\"compare-source-10-compare-result-title\" class=\"autool-compare-matrix-wrap\" role=\"region\" tabindex=\"0\">\r\n<table class=\"autool-compare-matrix\" data-autool-columns=\"1\">\r\n<caption class=\"autool-visually-hidden autool-table-caption--accessible\">Comparison of AUTOOL Automotive Oil &amp; Fluid Analyzers<\/caption>\r\n<colgroup>\r\n<col class=\"autool-compare-matrix__criteria-col\"\/>\r\n<col class=\"autool-compare-matrix__model-col\" data-compare-model=\"as501\" hidden=\"\"\/>\r\n<col class=\"autool-compare-matrix__model-col\" data-compare-model=\"as502\" hidden=\"\"\/>\r\n<col class=\"autool-compare-matrix__model-col\" data-compare-model=\"as503\"\/>\r\n<col class=\"autool-compare-matrix__model-col\" data-compare-model=\"as505\" hidden=\"\"\/>\r\n<col class=\"autool-compare-matrix__model-col\" data-compare-model=\"as506\" hidden=\"\"\/>\r\n<col class=\"autool-compare-matrix__model-col\" data-compare-model=\"as507\" hidden=\"\"\/>\r\n<col class=\"autool-compare-matrix__model-col\" data-compare-model=\"as509\" hidden=\"\"\/>\r\n<\/colgroup>\r\n<thead><tr>\r\n<th scope=\"col\">Product name<\/th>\r\n<th data-compare-model=\"as501\" hidden=\"\" scope=\"col\">AS501 Brake Fluid Tester<\/th>\r\n<th data-compare-model=\"as502\" hidden=\"\" scope=\"col\">AS502 Brake Fluid Tester<\/th>\r\n<th data-compare-model=\"as503\" scope=\"col\">AS503 Engine Oil Quality Tester<\/th>\r\n<th data-compare-model=\"as505\" hidden=\"\" scope=\"col\">AS505 Transmission Fluid Tester<\/th>\r\n<th data-compare-model=\"as506\" hidden=\"\" scope=\"col\">AS506 Brake Fluid Boiling Point Tester<\/th>\r\n<th data-compare-model=\"as507\" hidden=\"\" scope=\"col\">AS507 Power Steering Fluid Tester<\/th>\r\n<th data-compare-model=\"as509\" hidden=\"\" scope=\"col\">AS509 Coolant Boiling Point Tester<\/th>\r\n<\/tr><\/thead>\r\n<tbody><tr class=\"autool-compare-matrix__category\" data-compare-category=\"layout-group-1\">\r\n<th class=\"autool-compare-matrix__category-label\" scope=\"rowgroup\"><span class=\"autool-compare-matrix__category-label-inner\">Test Method &amp; Application<\/span><\/th>\r\n<td class=\"autool-compare-matrix__category-track\" colspan=\"1\" data-compare-category-track=\"\"><span aria-hidden=\"true\" class=\"autool-compare-matrix__category-progress\" data-autool-progress-order-ready=\"yes\" data-compare-category-progress=\"\"><span class=\"autool-compare-matrix__category-progress-label\">Slide \/ drag<\/span><span class=\"autool-compare-matrix__category-progress-meter\"><span class=\"autool-compare-matrix__category-progress-bar\"><\/span><\/span><span class=\"autool-compare-matrix__category-progress-count\" data-compare-category-count=\"\">1 \/ 1<\/span><\/span><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-1\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Detection Technology<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Pressure Boost Detection Technology<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Water-content screening; no hydraulic pressure generation or measurement<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">Optical Probe Technology<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Optical Probe Technology<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Sample Heating Technology<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Optical Probe Technology<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Sample Heating Technology<\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-1\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Operating Principle<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Brake Fluid (Water Content)<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Brake Fluid (Water Content)<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">Engine Oil (Transmittance)<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Transmission Fluid(Transmittance)<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Brake Fluid (Boiling Point)<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Steering Fluid (Transmittance)<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Coolant<\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-1\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Test Mode Selection<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Normal Mode<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Normal Mode\/Expert Mode<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">Gasoline Engine\/Diesel Engine<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Automotive Transmission Fluid<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Normal Mode\/Brand Mode<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Automotive Steering Gear<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Normal Mode\/Brand Mode<\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-1\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Boiling Point Reference Value<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"Yes\" class=\"autool-compare-matrix__mark\" data-autool-state=\"yes\" data-layout43-marker=\"\" role=\"img\">\u2713<\/span><\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"Yes\" class=\"autool-compare-matrix__mark\" data-autool-state=\"yes\" data-layout43-marker=\"\" role=\"img\">\u2713<\/span><\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-1\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Normal Mode<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">6 Types<br\/>ENV-4\u3001ENV-6<br\/>DOT3\u3001DOT4\u3001DOT5\u3001DOT5.1<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">3 Types<br\/>DOT3\u3001DOT4\u3001DOT5.1<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">DOT3, DOT4 and DOT5.1 (procedure-confirmed selections)<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">23 Coolant Brands<br\/>For ACDELCO\u3001BASF\u3001BOSCH\u3001CASTROL\u3001ENGINE_ICE\u3001EVANS\u3001FORD\u3001HONDA\u3001JOHN_DEERE\u3001KUNLUN\u3001MOBIL\u3001MOPAR\u3001NISSAN\u3001OMTECH\u3001PEAK\u3001PRESTONE\u3001RECOCHEM\u3001SHELL\u3001SKI-DOO\u3001ZEREX\u3001STAR_BRITE\u3001TOTAL\u3001TOYOTA<\/div><\/td>\r\n<\/tr><tr class=\"autool-compare-matrix__category\" data-compare-category=\"layout-group-2\">\r\n<th class=\"autool-compare-matrix__category-label\" scope=\"rowgroup\"><span class=\"autool-compare-matrix__category-label-inner\">Measurement &amp; Response<\/span><\/th>\r\n<td class=\"autool-compare-matrix__category-track\" colspan=\"1\" data-compare-category-track=\"\"><span aria-hidden=\"true\" class=\"autool-compare-matrix__category-progress\" data-autool-progress-order-ready=\"yes\" data-compare-category-progress=\"\"><span class=\"autool-compare-matrix__category-progress-label\">Slide \/ drag<\/span><span class=\"autool-compare-matrix__category-progress-meter\"><span class=\"autool-compare-matrix__category-progress-bar\"><\/span><\/span><span class=\"autool-compare-matrix__category-progress-count\" data-compare-category-count=\"\">1 \/ 1<\/span><\/span><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-2\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Temperature Unit Switching<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">\u2103\/\u2109<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">\u2103\/\u2109<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">\u2103\/\u2109<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">\u2103\/\u2109<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">\u2103\/\u2109<\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-2\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Temperature Measurement Range<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">0-85\u2103<br\/>0-185\u2109<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">0-85\u2103<br\/>0-185\u2109<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">0-320\u2103<br\/>0-608\u2109<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">0-85\u2103<br\/>0-185\u2109<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Diluted Coolant Boiling Point Range\uff1a<br\/>100\u00b0C~120\u00b0C(212\u00b0F~248\u00b0F)<br\/><br\/>Original Manufacturer Coolant Boiling Point Reference Range<br\/>106\u00b0C~191\u00b0C(221\u00b0F~376\u00b0F)<br\/>\r\n<\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-2\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Test Duration<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">10s Response<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">10s Response<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">10s Response<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">10s Response<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">16s Response<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">10s Response<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">20~40s Response<\/div><\/td>\r\n<\/tr><tr class=\"autool-compare-matrix__category\" data-compare-category=\"layout-group-3\">\r\n<th class=\"autool-compare-matrix__category-label\" scope=\"rowgroup\"><span class=\"autool-compare-matrix__category-label-inner\">Display, Probe &amp; Power<\/span><\/th>\r\n<td class=\"autool-compare-matrix__category-track\" colspan=\"1\" data-compare-category-track=\"\"><span aria-hidden=\"true\" class=\"autool-compare-matrix__category-progress\" data-autool-progress-order-ready=\"yes\" data-compare-category-progress=\"\"><span class=\"autool-compare-matrix__category-progress-label\">Slide \/ drag<\/span><span class=\"autool-compare-matrix__category-progress-meter\"><span class=\"autool-compare-matrix__category-progress-bar\"><\/span><\/span><span class=\"autool-compare-matrix__category-progress-count\" data-compare-category-count=\"\">1 \/ 1<\/span><\/span><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-3\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Backlit Display Screen<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">1.8-inch<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">2.8-inch<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">2.8-inch<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">2.8-inch<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">1.54-inch<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">2.8-inch<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">1.6-inch<\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-3\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Test Cable Length<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">26cm<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">26cm<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">80cm<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">80cm<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">4cm<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">80cm<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">130cm<\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-3\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Power Supply Voltage<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">3V<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">6V<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">6V<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">6V<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\">12V<\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">6V<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\">10-14V<\/div><\/td>\r\n<\/tr><tr data-compare-group=\"layout-group-3\" data-compare-row=\"\">\r\n<th class=\"autool-compare-matrix__feature\" scope=\"row\">Hose Material<\/th>\r\n<td data-compare-model=\"as501\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Iron Oxide<\/div><\/td>\r\n<td data-compare-model=\"as502\" hidden=\"\"><div class=\"autool-compare-matrix__value\">304 Stainless Steel<\/div><\/td>\r\n<td data-compare-model=\"as503\"><div class=\"autool-compare-matrix__value\">Teflon<\/div><\/td>\r\n<td data-compare-model=\"as505\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Teflon<\/div><\/td>\r\n<td data-compare-model=\"as506\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<td data-compare-model=\"as507\" hidden=\"\"><div class=\"autool-compare-matrix__value\">Teflon<\/div><\/td>\r\n<td data-compare-model=\"as509\" hidden=\"\"><div class=\"autool-compare-matrix__value\"><span aria-label=\"No\" class=\"autool-compare-matrix__mark\" data-autool-state=\"no\" data-layout43-marker=\"\" role=\"img\">\u00d7<\/span><\/div><\/td>\r\n<\/tr><\/tbody>\r\n<\/table>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div><\/section><section class=\"autool-section autool-product-section--cool autool-section--downloads\" data-autool-surface=\"cool\" id=\"autool-download\"><div class=\"autool-layout-container\">\r\n<header class=\"autool-section-head\"><p class=\"autool-subhead\">Manual &amp; Support<\/p>\r\n<h2 class=\"autool-title\">Find the Manual and Fluid-Test Guidance<\/h2><\/header><div aria-label=\"AS503 manual download and setup support\" class=\"autool-product-rail autool-resources-grid autool-mobile-rail\" data-autool-rail=\"resources\">\r\n<article class=\"autool-resource-download autool-resource-panel\"><div class=\"autool-resource-media\">\r\n<img loading=\"lazy\" alt=\"AUTOOL AS503 user manual cover\" decoding=\"async\" height=\"300\" loading=\"lazy\" src=\"https:\/\/autoolstore.com\/wp-content\/uploads\/2024\/03\/autool-as503-user-manual-pdf.jpg\" width=\"212\"\/>\r\n<\/div><div class=\"autool-resource-body\"><span class=\"autool-resource-meta\">Manual \/ PDF<\/span><h3>AUTOOL AS503 User Manual<\/h3><p>Open the PDF manual for AUTOOL AS503 gasoline and diesel oil testing, optical-probe use, temperature measurement, result interpretation, cleaning, safety and troubleshooting support.<\/p><div class=\"autool-resource-actions\"><a class=\"autool-product-button\" href=\"https:\/\/autoolstore.com\/wp-content\/uploads\/2024\/03\/autool-as503-user-manual.pdf\" rel=\"noopener\" target=\"_blank\">Download Manual<\/a><\/div><\/div><\/article><aside class=\"autool-resource-panel autool-section--support\" id=\"autool-support\"><div class=\"autool-resource-body\"><span class=\"autool-resource-meta\">Setup Help<\/span><h3>Need Help Choosing the Right Setup?<\/h3><p>Contact AUTOOL Store before ordering for help with manual versions, installation steps, compatibility, accessories, safe-use instructions, or after-sales support.<\/p><dl class=\"autool-support-list\"><div><dt>Email<\/dt><dd><a href=\"mailto:support@autoolstore.com\">support@autoolstore.com<\/a><\/dd><\/div><div><dt>WhatsApp<\/dt><dd><a href=\"https:\/\/wa.me\/8618926477404\" target=\"_blank\" rel=\"noopener\">+86 189 2647 7404<\/a><\/dd><\/div><\/dl><div class=\"autool-resource-actions\"><a class=\"autool-product-button\" href=\"mailto:support@autoolstore.com\">EMAIL<\/a><a class=\"autool-product-button\" href=\"https:\/\/wa.me\/8618926477404\" rel=\"noopener\" target=\"_blank\">WHATSAPP<\/a><\/div><\/div><\/aside>\r\n<\/div>\r\n<\/div><\/section><section class=\"autool-section autool-product-section--warm autool-section--package\" data-autool-surface=\"warm\" id=\"autool-box\"><div class=\"autool-layout-container\">\r\n<div class=\"autool-package-layout\">\r\n<figure class=\"autool-package-media\">\r\n<img decoding=\"async\" alt=\"AUTOOL AS503 packing list showing main unit retail box and user manual\" loading=\"lazy\" src=\"https:\/\/autoolstore.com\/wp-content\/uploads\/2025\/10\/b1a9056a-0d0b-41d6-90db-3f5f89c68c16.png\"\/>\r\n<\/figure>\r\n<div class=\"autool-package-copy\"><p class=\"autool-subhead\">Package Contents<\/p>\r\n<h2 class=\"autool-title\">See What Comes in the Box<\/h2><ul aria-label=\"AS503 package contents\" class=\"autool-package-list autool-product-rail\" data-autool-rail=\"package\">\r\n<li>\r\n<span>Main Unit<\/span><strong>AUTOOL AS503 engine oil quality tester with integrated flexible probe<\/strong><\/li>\r\n<li>\r\n<span>Item<\/span><strong>Probe Built-in 800mm PTFE \/ Teflon hose probe<\/strong><\/li>\r\n<li>\r\n<span>Documentation<\/span><strong>User manual<\/strong><\/li>\r\n<li>\r\n<span>Package<\/span><strong>AS503 retail box<\/strong><\/li>\r\n<li>\r\n<span>Item<\/span><strong>Power Requirement Requires 4 \u00d7 1.5V batteries; inclusion should follow the final package listing<\/strong><\/li>\r\n<\/ul><\/div>\r\n<\/div>\r\n<\/div><\/section><section class=\"autool-section autool-product-section--white autool-section--faq\" data-autool-nav=\"FAQ\" data-autool-surface=\"white\" id=\"autool-faq-description\"><div class=\"autool-layout-container\">\r\n<header class=\"autool-section-head\"><p class=\"autool-subhead\">Buyer Questions<\/p>\r\n<h2 class=\"autool-title\">Fluid Fit, Method and Result Questions<\/h2><\/header><div class=\"autool-faq-grid\">\r\n<details><summary>What Does The AUTOOL AS503 Test?<\/summary><div class=\"autool-faq-answer\"><p>AS503 tests gasoline and diesel engine lubricating oil by checking oil transmittance with an optical probe. It also displays the current oil temperature to help users evaluate engine oil condition during maintenance.<\/p><\/div><\/details><details><summary>Can AS503 Test Both Gasoline And Diesel Engine Oil?<\/summary><div class=\"autool-faq-answer\"><p>Yes. AS503 supports separate gasoline engine and diesel engine oil mode selection. Select the correct engine type before starting the test.<\/p><\/div><\/details><details><summary>How Should I Read The Transmittance Result?<\/summary><div class=\"autool-faq-answer\"><ul><li>When transmittance is between 100% and 50%, oil replacement is generally not required.<\/li><li>When it is between 50% and 30%, the screen shows a warning symbol.<\/li><li>When it drops below 30%, the tester beeps and suggests immediate oil replacement.<\/li><li>Use the result together with actual vehicle service requirements.<\/li><\/ul><\/div><\/details><details><summary>Which Engine Oils Are Not Suitable For AS503?<\/summary><div class=\"autool-faq-answer\"><p>AS503 relies on optical detection, so it is not suitable for engine oils containing molybdenum disulfide (MoS\u2082), organic molybdenum, graphene, or similar substances. These additives may affect optical analysis results.<\/p><\/div><\/details><details><summary>Does AS503 Support Suzuki J20A Engine Testing?<\/summary><div class=\"autool-faq-answer\"><p>No. AS503 does not support the Suzuki J20A engine. Contact AUTOOL Store for compatibility help with another model or engine.<\/p><\/div><\/details><details><summary>How Often Should I Test Engine Oil?<\/summary><div class=\"autool-faq-answer\"><p>A practical reference is to check engine oil every 5,000-10,000 km, depending on oil type, driving conditions, vehicle age, engine condition, and the maintenance schedule recommended for the vehicle.<\/p><\/div><\/details><details><summary>What Batteries Does AS503 Use?<\/summary><div class=\"autool-faq-answer\"><p>AS503 uses 6V power from 4 \u00d7 1.5V batteries. Battery inclusion should follow the final package listing, so do not assume batteries are included unless confirmed.<\/p><\/div><\/details><details><summary>What Should I Do If The Hose Or Probe Gets Stuck?<\/summary><div class=\"autool-faq-answer\"><p>Do not force the hose or probe out if it becomes jammed. Stop operation, check the surrounding position carefully, and contact support if you are unsure how to remove it safely.<\/p><\/div><\/details><details><summary>What Is Included In The Box?<\/summary><div class=\"autool-faq-answer\"><p>Package contents: AS503 main unit with integrated flexible probe, user manual, and retail box. AS503 requires 4 \u00d7 1.5 V batteries; battery inclusion follows the selected package listing.<\/p><\/div><\/details><details><summary>What Is The Difference Between AS503 And Other AUTOOL Fluid Testers?<\/summary><div class=\"autool-faq-answer\"><ul><li>AS503 is for gasoline and diesel engine oil transmittance testing.<\/li><li>AS501 and AS502 are brake fluid water content testers.<\/li><li>AS505 is for transmission fluid transmittance.<\/li><li>AS506 is a brake fluid boiling point tester.<\/li><li>AS507 is for power steering fluid transmittance.<\/li><\/ul><\/div><\/details><details><summary>How Long Is The Warranty?<\/summary><div class=\"autool-faq-answer\"><p>Main unit: 3-year warranty. Standard accessories: 1-year warranty. <a href=\"https:\/\/autoolstore.com\/warranty-policy\/\" rel=\"noopener\" target=\"_blank\">Warranty Policy<\/a>.<\/p><\/div><\/details><details><summary>Can AS503 Replace Professional Oil Laboratory Analysis?<\/summary><div class=\"autool-faq-answer\"><p>AS503 provides quick oil-transmittance and temperature checks for maintenance screening. Use professional oil analysis when chemical composition or wear-metal data is required.<\/p><\/div><\/details>\r\n<\/div>\r\n<\/div><\/section><\/main><\/div>\r\n\r\n","protected":false},"excerpt":{"rendered":"<ul>\n<li><strong>Optical Engine-Oil Screening:<\/strong> Measure engine-oil transmittance to screen for contamination and suspended particles that reduce transparency.<\/li>\n<li><strong>Gasoline + Diesel Oil Modes:<\/strong> Choose separate gasoline or diesel engine-oil modes for the intended lubricant check.<\/li>\n<li><strong>800 mm PTFE Probe:<\/strong> Reach oil around the engine bay with the flexible, oil-resistant hose probe.<\/li>\n<li><strong>Oil Temperature Display:<\/strong> View current oil temperature in \u00b0C or \u00b0F alongside the screening result.<\/li>\n<li><strong>Status + Sound Prompts:<\/strong> Use screen symbols and sound reminders to distinguish acceptable, attention, and replacement guidance.<\/li>\n<\/ul>\n","protected":false},"featured_media":62545,"comment_status":"open","ping_status":"closed","template":"","meta":{"_gspb_post_css":""},"product_brand":[448],"product_cat":[1063,1068],"product_tag":[956,940,939,946],"hf_cat_product":[4540],"class_list":["post-40201","product","type-product","status-publish","has-post-thumbnail","product_brand-autool","product_cat-automotive-repair-testing-equipment","product_cat-oil-analysis-tester","product_tag-fluid-testing","product_tag-measurement-tools","product_tag-multi-warehouse-shipping","product_tag-package-options","first","instock","sale","shipping-taxable","purchasable","product-type-variable"],"meta_box":{"autool_archive_segment":"Pressure testing","autool_primary_use_case":"Pressure testing for engine, fuel, air or cooling systems","autool_customer_focus":["measurement accuracy","package choice","warehouse \/ delivery location"],"autool_source_summary":"- Pressure Checks Made Clear: Built for targeted pressure diagnosis in fuel, oil, cooling, or air systems where confirmation matters before repair. - Package Difference Is Clear: Single-unit and bundle options are easier","autool_model_family":"AS503","autool_voltage_options":"","autool_ship_from_options":"Germany\u3001United States\u3001United Kingdom\u3001China","autool_package_options":"AS502+AS503+AS505+AS507\u3001Only AS503","autool_accessory_options":"","autool_data_confidence":"site-content-derived","autool_manual_review_notes":""},"_links":{"self":[{"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/product\/40201","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/comments?post=40201"}],"wp:attachment":[{"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/media?parent=40201"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/product_brand?post=40201"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/product_cat?post=40201"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/product_tag?post=40201"},{"taxonomy":"hf_cat_product","embeddable":true,"href":"https:\/\/autoolstore.com\/wp-json\/wp\/v2\/hf_cat_product?post=40201"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}