check oil level with engine warm or cold?

Never found it to be much of a factor. I agree with 1/4" below high mark as being a good sweet-spot for intital level after an oil change. That ensures you aren't overfilled, and gives lots of elbow room on the down side.

Transmission fluid levels are often spec'd to be checked hot. I've always found that to be difficult and contradictory, and settle on cold check for them as well.

Most consistant measures are likely when taken after an overnight sit.

 

Is your hot check while the engine is actually running? That's the only reason I could see for such a disparity.

Regarding being 1/4" over top mark when cold, I'd put that down to a service department who's first priority is giving "full measure", and of course charging you for it. While that's not gross overfill, it's an irritant. Better to fill it a bit under top mark and give you the remainder of the bottle.

Overfill is detrimental to mileage, and if overfilled enough can do damage to seals.

That's assuming your getting the oil changed by pro's.

 

I've found the 0w20 oil to be very clear and almost impossible to see on the dip stick sometimes.

 

ooops sorry. I mixed your join date of 2010 with the model year.

 

You can check it hot or cold. But it must be off and you need to wait at least 10 minutes after you shut it off for all the oil to drian own into the oil pan. If you check it right after you shut it off it will read lower than it really is.

 

I only check when cold. When traveling and filling with gas when checking of course the engine will be warm. I use 0-20 in my G2, so it is even harder to see. You must get the angle and light perfect to see it. I don't check until after the fill up in order to let the oil drain into the pan. I would not use 5-30. I believe Toyota even specifies 5-20. 0-20 or 5-20 will give you better FE and help lub. the engine on cold starts.For what its worth, H

 

I assume that you are checking the engine oil when the engine is hot, and you have waited at least 5 minutes after making the car IG-OFF. Remove the dipstick and wipe it off, then reinsert it and remove it again. Hold the dipstick so that its flat surface is reflecting the available light into your eyes. Then you should be able to see what portion of the dipstick is wet with oil.

In any event, if you see that the oil dipstick level is 1/4" above full when the engine is cold and the car is IG-OFF, then you need to drain ~1/4 quart, to bring the oil level near the full mark.

 

+1. Works every time for me - hot or cold. Good luck!

 

I haven't done it yet on my Prius, but on other cars I have noticed no obvious difference in oil level between hot after sitting 10 minutes and cold after sitting overnight in the same place. Since the laws of physics also apply to a Prius, I dont expect anything different on my Prius.

 

Hi everyone !!
I have a toyota prius 2008-2009 and i bought it before 1 week and i wanted to cheek motor-oil level but i have problem with dipstick that i cannt pulled up its so hard id ont know why ?!! Can some one here tell me why ?!? Thanks alot

 

Hej

The dipstick is somewhat tighter on the Prius, not loose like on many cars. Just pull a bit harder, it should come as there is nothing unusual about it otherwise.

 

I have never heard of checking oil when engine is cold. ever. I learned to always check oil with a warm engine.

 

I have always checked levels when cold.