Oil Level Check

[MattstaF6]

Hi Guys

Quick question. Whats the reason my Instruction manual for my F6 tells me to check the engine oil level when the engine is hot.
I used to check the level in the morning when the car was sitting all night on a level surface.
Have i been checking the level wrong. Should I be getting the engine to normal operating temp and then switch the car off and wait a few minutes and then check? Whats the reason for this?