8 Speed Auto for HD trucks
Apparently, ZF is making an 8 Speed HD trans that can handle 1000 lb-ft. 2020 release date. I see it as the next trans in the Ram 2500 and 3500s. LINK
Forum Discussion
Ralph Cramden wrote:
The end ratio of high gear is going to be in the neighborhood of 0.68/1 no matter if it's a 6 speed or a 20 speed. Assuming we're talking HD gassers, which hit their powerband at a high rpm, other than squeezing an almost impossible to notice MPG gain the extra gears don't give you all that much.
Now in a truck that's used by Joe Schmow to haul a couple of bags of mulch between work commutes, or Soccer Sally to haul home the groceries, which are what the vast majority of light duty trucks are used for it makes all the sense in the world to have some extra ranges between top and bottom. In a HD truck being used as an HD truck it does not make as much sense. I suspect I am getting an 8 or 10 speed through no choice of my own the next time I buy a truck, but my current 2015 GMC 2500 with its 6 speed has more than enough intermediate gears, I don't know what I would be gaining with 2 or 4 more other than more heat from more shifts and additional parts to wear or fail internally. I was not looking for mileage when I bought it.
Some posters mentioned how well they like the 8-10 speeds in their cars or 1/2 tons, and I'm sure they work great, improving performance/mileage. However, Ralph makes good points, concerning HD truck use, even with a gasser.
Jerry
