i have a 93 ford ranger with a 3 litre engine and oil pressure when cold is about 55 and 18-20 ai idle and 40 at 2000 r.p.m when hot. The good folks out there tell me this is completely normal did this engine have a problem with oil pressure as i have owned old chevys and fords that when hot would be 30. the engine has new bearings and pump and is spottless inside. and since it appears that this is the nature of the beast is there one oil better than another for not thinning out so much i know that i am being a pain but it is my son,s truck who has just bought a house near ottawa ont. and is broke aqnd i want to be sure that he has no more problems.. thanks again sam

 

I like Castrol GTX.

 

it doesn't matter which oil you use it will thin when hot. besides with the specs you have given the engine is in fine shape. 40 psi at 2,000 rpm is above the spec and idle pressure does not matter as long as you have 10 psi for every 1,000 rpm so at idle you only need 8 to 10 psi. but ford does not give a spec for idle pressure.