The fewer number of cylinders, the less frictional losses you will have (fewer bearings, less circumferential piston area, less pumping losses, etc.). This makes the engine more efficient.

Also, trucks depend on up time. The fewer cylinders there are, the less there is to break.

Randy

 

does anybody have anymore info on those new 6 speed rwd transmissions that Eric linked to? I would really love to have an idea of the gear ratio spread. I have seen the ratios listed once before, but don't remember where I saw it. I think it was in info from the STS. For some reason I think I recall seeing that the first gear ratio was a 4.0 and the 6th gear isn't much lower than the current 4L60E, but since they will be using less rear gear, it works well.

 

and then after more searching, I found this...

 

Sounds nice. I wonder if this has anything to do with the 6 speed autos that ford and dcx released after "working" with The General?

 

The new X22F 6-speed transaxle was co-developed by Ford and GM, and they do supply each other some components but each will eventually assemble the transmissions themselves (I've heard that they may supply complete tranaxles to each other during the ramp-up process).

GM's new RWD transmissions have nothing to do with the Ford 6-speed RWD offerings; the blue oval guys get their gearboxes from ZF and Aisin. DCX has no 6-speed RWD transmission at this time; the W5A580 used by Chrysler is a repackaged version of the NAG1 gearbox developed by Mercedes. The new 7-speed NAG2 (AKA 7G-Tronic) gearbox used in new M-B products is also exclusive to Mercedes.