(I just noticed, i meant 0W20) I was just wondering! Didnt know if you guys thought it was too light. I know in the semi I drive of course it uses a heavy oil but my truck doesnt do as hard of work as it does. And I know it being a "Fuel Economy" oil its not going to help out much but maybe if you have a good hill with a tail wind you might gain some!

 

By Ford standards, a 0W30 is "heavy," since they are spec'ed for a 5W20. I haven't looked up the Mobil 1 0W30 specifically, but most in that viscosity grade tend to be on the light side of the 30 grade area so I don't think your truck will much notice a difference... assuming your '04 has a VCT engine. If it's an '04 Classic, you are fine. The 0W30 oils are particularly good in the cold start and cool start areas, flowing very well in those warmup periods. IMO, it's an OK choice if you want to stray away from the 5W20 doctrine. FYI, there are 0W20 oils too!

Warning: Semi-Hijack

Interestingly, I am running an experiment now on my '05 5.4L VCT engine and using the Motorcraft 10W30 HDEO... which is designed for the Power Strokes. I have been datalogging VCT operation before and after the change and I don't see any differences in how it operates according to those charts. Oil pressure (I have a real Isspro OP gauge installed) went up, of course, but beyond that I don't see a lot of difference in how the truck operates. I do note the engine is a little quieter. The Modulars are kinda "rattly" by nature and the heavier oil tends to dampen the phasers and timing chains a bit. Fuel economy... nothing to report yet. In theory, I could see a drop. We'll see how much. My driving situation... long runs where the engine gets fully warmed up... is conducive to a heavier oil.

And, to answer the inevitable question of why, I answer that I'm not doing it because I think optimal for my truck. I'm doing it to consolidate the oil supply to one oil for my "fleet" of trucks, car, farm tractors and small engines. Because of the VCT, the 5.4L was the only engine that I worried about, so I'm experimenting first and checking in every way I can. I'm willing to take the slight hit in fuel economy if that's the only downside I find. I got to thinking about this after reading about the 10W30 spec in Australian VCT Modular engines and the 10W40 phaser noise bandaid TSB from Ford. Unless something really bad pops up, I will test this oil after about 7500 miles. It's avery robust oil, so it should do well in most ways.

 

I just edited my post. I meant to sat 0W20. But yeah I'm doing to same. I use that in my truck, wife's suv m, and I'm doing research to see if I can use is it my jetski. Probably can't but would great if I could.

 

Well, a 0W20 will give you better cold and cool flow characteristics, so go fer it!