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
For big trucks, the gear count came down not up as engine tuning increase the power ban in some cases. We had 5x4 and 5x3 transmission setups with a 5 speed main tranny and a 4 or 3 speed brownie. Creating 20 or 15 forward gears. Then the 13 speeds in one box, down to 9 as power bans increase in widths. Eaton Autoshift has 18 gears forward a 4 in reverse, and a clutch to start moving, not a torque converter.
It is a mixed bag depending on application.
Here is a write up on what is happening in heavy duty trucks.
https://www.truckinginfo.com/154981/transmission-trends
For pickups going from 4 speed autos to 6 was a great improvement. Ford and GM/Allison started in 2000ish with 5 and switched to 6. I am not sure in the HD pickup arena the that going to 8 or 10 will make a large improvement like going to 6 did.
For a hand full of users like Cummins12V98 having another OD for freeway cruising would be a benefit, however delivering power via a .50 to 1 third overdrive might be self defeating.
The question remains do diesel trucks need more gears within the same range as the 1-6 ratios that we have now. For my use, the answer is no. Better programming to assure the combination was always in the best gear for the conditions might be more beneficial than more gears(that would require similar programming to be effective).
The RAM/Cummins in the pipe line(for 2019 r 2020 models) with all smog stuff down stream of the engine, might be a much bigger improvement to mileage than any transmission change.
It is a mixed bag depending on application.
Here is a write up on what is happening in heavy duty trucks.
https://www.truckinginfo.com/154981/transmission-trends
For pickups going from 4 speed autos to 6 was a great improvement. Ford and GM/Allison started in 2000ish with 5 and switched to 6. I am not sure in the HD pickup arena the that going to 8 or 10 will make a large improvement like going to 6 did.
For a hand full of users like Cummins12V98 having another OD for freeway cruising would be a benefit, however delivering power via a .50 to 1 third overdrive might be self defeating.
The question remains do diesel trucks need more gears within the same range as the 1-6 ratios that we have now. For my use, the answer is no. Better programming to assure the combination was always in the best gear for the conditions might be more beneficial than more gears(that would require similar programming to be effective).
The RAM/Cummins in the pipe line(for 2019 r 2020 models) with all smog stuff down stream of the engine, might be a much bigger improvement to mileage than any transmission change.
