Good article on the new 6.7 on pickuptrucks.com saying that there will be two versions of the new Powerstroke used. The higher rated engine will be used in the F-250, F-350, and F-450 pickups while a derated version with a different turbo will be used in the F-450 and F-550 Chassis-cabs. The article still doesn't give any specific numbers yet though.

Ford and the Case of the Case of the Missing Compressor - PickupTrucks.com News

 

sweet find John. I`d like to see some numbers as well as I plan on buying one

 

umm why would a derated version be used in the higher GVW vehicles ???

surely the higher GVW trucks need the extra grunt...

you sure the numbers arent backwards ?

 

That's how it is now. I believe some F-450s and all F-550s have derated 6.4L engines. 325 HP I think.

 

I'd say it's accurate. Remember the 6.7 Cummins in the medium duty trucks and the Ram Chassis-cabs is derated for longevity. And as Crazy001 said, the current 6.4 in the F-450 / 550 is derated to 325 HP and 600 or 625 TQ for the same reasons.

Yeah, you're right but it's derated via the engine program / electronics. The 6.7 appears to be derated through the use of a completely different turbo for the chassis-cabs. It may be that it's electonically limited also.

 

Good point, Powerstroke72. Also, if I remember right, the pre-2010 MaxxForce 7 engines use a single borg-warner turbo and have less than 300 horsepower. Seems that when they put an engine into a heavier platform they aren't willing to warrant it for as much power due to the increased stress.

 

Tom, I think you're right about the Max-Force too. All of the engines like it that I've seen used in heavier applications have been derated in some form or fashion. A lot of the time too, I've seen them putting out lower HP ratings while sometimes putting out higher TQ ratings. Either way, the argument I've always heard attributed it to longevity of the engine under more stressful applications.

The other thing that sticks out in my mind also, is that most of these medium duty trucks also have much steeper gear ratios in the differentials.

 

Seems about right. Those 450s and 550s are geared really low. 4.55s and 4.88s. We got a 2000 F-550 with the 7.3 and the 6spd. ZF. You really have to work the engine to get to 40. Want to go 45, hit 5th.

 

GM deoes the same thing with the Duramax in the 4500 and up. It's my understanding the derating the engine increases the engine life.

Rob