Should I check my oil hot or cold
Cold before you start the engine will give the most accurate reading. If you are on a trip and check while filling up your tank at least 5 minutes for the oil to drain back into oil pan. 10 minutes is even better.It is also a good practice to pick one day a week to check the oil level such as Sat .
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I’d check it hot
Drive the car for several miles
Park the car in the driveway
shut off the car
go in the house and drink a cup of coffee, which will probably take a few minutes
Go back outside and check the engine oil level
I’m of the opinion that automotive fluids should be checked at normal operating temperature
Tester
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I say to check it which ever way is most convenient and gives the easiest to read results. I check my cars stone cold and I don’t even pull the dipstick out all the way, but rather pull it just enough to see the level. No muss, no fuss. I’ve compared those readings with hot readings and they are similar. My exception to the cold check is checking at every gas fill-up on looong road trips.
I’ve had cars with convoluted dipstick tubes and sticks that flat out won’t give a workable reading when hot. I guess oil gets trapped in the tube or some darn thing. Cold works on those rascals.
Also, I keep my oil clean and it is sometimes nearly invisible when hot, but cold, I can see a line of reflection indicating the level.
If you do check it hot, a tip that helps some is to pull out the stick and wipe it. Let it cool to the touch and then insert it and remove it promptly. It seems the hot oil clings to a relatively cool piece of metal better and leaves a better, more distinct indication.
Cold, hot, in between, aren’t nearly as important as checking frequently. You’ll soon learn your car’s reading idiosyncracies if any exist. Hint: Check it cold and hot a few times and compare.
The fact you want to check your oil and do check your oil moves you to the front of the pack!
CSA
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On the other hand transmission fluid must be at operating temperature with the engine idling in N/P when checking. That is due to the variable amount of fluid that can be suspended in the torque converter, etc. When the engine is off fluid settles into the pan.
For the average car owner the somewhat contradictory situation re transmission fluid and motor oil levels can be confusing.
Doesn’t really matter just as long as you check it periodically.
I’ve always checked oil with the engine cold after the car has been sitting for a while.
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Another vote for checking it cold (or at least after it’s drained back down into the oil pan). If the amount of oil in the top end of a hot engine is negligible, so is the lack of expansion when checking cold.
One word of caution on checking it hot: some vehicles with the auto start/stop tech hold the oil in suspension longer and you’re supposed to wait at least 15 minutes after shutting down the engine to get an accurate reading.