Skip to main content
Skip to page content

Difference between motor oil and transmission fluid

“I work at an auto parts store and customers ask the difference between motor oil and transmission fluid. What would your explanation be? Quick and simple – to the point.”

Tim McIlhenny, Bremerton, Washington


Motor oil is for your vehicle's engine. Transmission fluid is used by your steering system to keep its parts moving smoothly. A couple of differences are the following: An engine oil is designed to deal with the products of combustion, whereas an automatic transmission fluid (ATF) does not see contaminants from fuel burning. An ATF is basically a closed system and the lubricant must last for a long period of time. An engine oil must be drained to remove contaminants after a relatively short time and/or mileage compared to an ATF. Similar additive component types are used, but at different levels and different chemistries. In an ATF, clutch friction is a very important consideration.


Go back to all questions
Energy lives here