I am purchasing 250 6.0 next month. I always use pennzoil in my f150 5/30. what do you think of pennzoil 15/40 for this new truck. Would this oil be as good as rotella or motorcraft. please the whole truth and nothing but the truth.Thankyou !

 

It would probably work ok, but it's not what I would use. I'd use Mystik, Rotella, or Delvac. In that order of preference.

 

Use what the owner's ,manual calls for , weight wise that is. The engineers know a hell of a a lot more than we do. I have always followed the book and have gotten incredible(400,000 mi on one vehicle) life out of my trucks.

 

Rotella 15-40. I've always heard that Pennzoil is bad for the engine, but EVERYONE has heard bunk like that before.
If Rotella is good enough for the OTR million-mile trucks, is it not good enough for you?

 

I've used it before I switched to Mobil 1 Delvac 5-40. It is a very good oil. No worries about it either, it's rated CG-4 and all the others (I can't remember them all right now). It's good enough for the big rigs so it will be more than enough for your 6.0
Synthetic is much better though.

 

This appears to be a fairly new modular OHC motor. A 40 weight should not be necessary unless the engine is worn enough that the oil pressure is below spec. I would run a 30 weight in it, probably Valvoline Maxlife. But if you want a thicker 30 weight and a heavy duty motor oil additive package, Citgo Ultralife ("high mileage") 10w30 is in the upper end of the 30 weight range and has hefty doses of zinc and phosphorus.

 

Tallpall...the 6.0 is the Diesel 365 from International isn't it?

Didn't Ford send out a TSB on running the new 365's on 10W30 diesel or something? Just asking.

I'd stick with Rotella (Dino for break in, Synthetic after 10,000 miles) or Delvac. I'm a HUGE Motorcraft fan...but those two diesel oils cannot be beaten.

 

Oops. I forgot about diesels. I was thinking it had the V10 gasser. I really don't know what they run in the diesels.

 

15w40 is the normal viscosity specified for most diesels. I THINK they say in winter you're supposed to use a diesel rated 10w30 on the PSD's because of some fuel delivery issue caused because the injectors use engine oil in their normal operations, and 15w40 becomes too thick.