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
Me Again wrote:
With diesel engines wide flat torque curves, I just do not understand the need for more than 6 gears. Except for maybe RAM 68RFE that has tall 1st and 2 gears. Might be easier to just fix the ratios of the existing box than add more gears.
But how about two reverse gears, with a granny gears for the second one. Would be great for spotting trailers etc.
You want a gear that can give you max HP at WOT. More gears make it more likely you will have one instead of being in between gears and shifting back and forth as you go from a gear that doesn't give you enough power to one that puts you on the rev limiter and back again. Also 900 Lbft at 2000 RPM makes about 340 HP, at 2500 RPM it is closer to 428 HP. If you had an in between gear you could make 386 HP at 2250 RPM. So more gears can actually mean less shifting.
