Ii have a 2000 f150 5.4 2v. My question is which oil viscosity should I run since it seems all manufactures have gone to 5w20 or 0w20?
My old girl's book says 10w30. What do you run in your older 5.4?
If there are any Ford power train guys out there please advise.

Louis

 

Still rock'n 5w20 @ 198k but I think I will switch to 5w30 next Summer . Unless I go get ambitious and Over haul the engine

 

tlbond........ you are in Texas.. It is a lot higher ambient temp than in Iowa or Minnesota. A slightly thicher oil in Texas like 10w30 would act a lot like 5w20 in Minnesota. If you have been using 10w30 and its working good, I would stick with that. 5W20 is going to give you a lower oil pressure with a hot motor.

 

5w-20 is what I use.
People a lot smarter than me and know a whole lot more about lubrication and engine design say use 5w-20, and millions of miles have been driven on 5w-20, so that is what I use.

 

My 2003's oil cap says 5w-20 on it.

 

The spec was changed for the 2001 model year I believe, it was back spec'ed to previous models that previously were 5w-30.
Some say it is CAFE only reasons, but there were issues with the timing chain tensioner with thicker oil, and 5w-20 helps with that.

 

Check that manual again... The 5th printing of the 2000 manual says 5w-20

My 1997, the first year of the modular engines in the F-150, is 5w-30. I don't think 10w-30 was ever spec'd for the modular engines, not even the 4.6L, which started out in cars in the early 1990's. They spec'd 5w-30 for many years on those, not 10w-30.

 

if you have a high mileage engine use 0w30 casteroil edge best ive seen by far