8 Speed Auto for HD trucks

wilber1 wrote:

Me Again wrote:
Maybe Diesel/Electric will take over like Locomotives and Ships!

Basically that is the Volt, except it isn't diesel and it has a battery pack to store energy.

The Volt is a drastically different solution from a diesel/electric train even though there are some parallels the reasons and benefits have little to do with each other.

Trains: Steam engines (similar to electric motors) could deliver maximum torque from zero RPM. Also you could manage the power delivery very well and you didn't have the issue of stalling the engine like with an ICE. As diesels came out and grew in HP and you moved to multiple engine trains, development of a mechanical transmission that could handle the massive HP and coordinate between multiple engines while keeping the diesel in a very narrow power band quickly became impractical. So even though it was less efficient (compared to a mechanical transmission once up to speed), the losses were small enough that using a generator and electric motors as the transmission was better since it allowed that max torque at zero RPM, allowed you to keep those big slow turning diesels at the ideal RPM and made it simple to coordinate multiple engines via electronic controls. (trains more than make up for any efficiency losses by using ultra low rolling resistance wheels and aerodynamic benefits of 5' headways). The generators/electric motor function almost exclusively as a transmission.

Volt: The Volt does have a function that will do gas-electric operation but it's a backup function and much less efficient operation. Ideally, the Volt will run 80-90% of the time on battery electric and the gas-electric operation is only rarely used. The gas-electric mode is only a backup for those (ideally) rare times when the battery runs down. Once in gas-electric mode, efficiency drops below what an equivalent standard ICE car will provide. As long as it's a rare situation, it's a good trade off.

It's unlikely to take over the truck market as we have mechanical transmissions that can easily handle 80,000lb trucks. For our little non-commercial trucks it's not even close to pushing the limits. Then you have the weight and space considerations. Your transmission isn't really that heavy compared to a large generator and electric motors. It's possible we will see a Volt type setup but it will likely be focused on light duty grocery getter 1/2 ton trucks that rarely do any significant towing. If you get a 40 mile range under battery (similar to the volt), once you hook up a big trailer, that will likely be under 20 miles and most camping trips are far beyond that range, so within the first 15-20 minutes of driving, you will switch to the less efficient operation.