I know Ford says to use 5w-20 which is what I have always used in my truck. That is until my last oil change. I have always gotten my oil at costco, they have mobile 1 cheaper than I can find anywhere else. Last weekend I went to buy some but they didn't have any 5w-20 just 5w-30 and 10w-30. I used the 5w-30, is there any reason this could ever be an issue?

 

I'd say no problem, just stay with the brand you've been using.

 

Probably ok with the 5W-30. The city of South Daytona destroyed a whole fleet of 4.6 cop cars by putting 10W-40 in the engines.

Kurt

 

I run 0W40 in mine. It exceeds the viscosity requirement at both ends. You can always go lower in front of the W and higher after the W but not the other way around.

 

Thanks for the info. Sounds like I'll just stick with it.

 

My Ford owner's manual says 5w-30.

Super
Premium
Motorcraft
Motor Oil

5W-30

 

2000 and up 5w20
1999 and down 5w30

 

Ive run 10W-40 in my 5.4 for over 100000 with NO problems. Im not planning on whiching now.

Im in NC, We can get HOT in the summer

 

Run what the manufacturer recommends.