When I changed my oil last I was just above the Full mark, 5000km later I'm at the Low mark. I won't have time to change the oil until next week so I topped it up.

My question is how do you know how much to top up? what is the actual volume difference between L and F?

If this is vehicle specific it is a 2008 WRX using Motul 8100 5w-30.


It is very definitely vehicle specific. Every manufacturer is going to or can do it differently, and they do. Think of how many liters your Subie holds for a fresh oil change and for that in a semi-truck. We are talking the difference of quarts to gallons in total.

To answer your question, this is basically a trial and error way to do business. You put an "amount" into the crankcase and check the dipstick for the level. If too low, add a bit more. You ultimately get used to how much is needed in your specific vehicle by your past experience.

If I were a guessing man, I'd probably put the difference between the high/low marks at ~1/2 liter (or quart ... depending on your local) in most non-commercial vehicles. That is what experience has shown me, anyway.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.