Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Oil pressure

Under what conditions is the oil pressure in a typical gasoline engine highest? On the gas, off the gas, idle, what? Rocketman

I’m going to say, the highest oil pressure is on a cold start.

It would be highest when it takes the most effort to pump through the engine, so that would be when the engine is cold. Higher still when a cold engine is revved some.

All engine oil pumps have a spring loaded pressure relief valve that shunts excess oil flow back to the oil pan if the pressure gets above a certain point. It is the pressure that this valve is set for that determines the oil pressure of an engine at speeds much above idle.