Why not diesel electric trucks?

jdc1 wrote:
You wouldn't need the generator system to charge the battery 100% of the time. Both the Clarity and Volt are plug-ins. You wouldn't need a 70kW battery pack either. Half of that would suffice.
https://www.nationalpump.com.au/calculators/guide-to-choosing-generator-to-motor-size/

I don't have a clue what size generator would be required to run an electric motor equivalent to say a 454 ICE engine. But, I'm thinking a smallish diesel generator to charge a 30-40KW battery pack that propels the electric motors. Would we see a huge increase in fuel economy? Would the total drivetrain outlast those of ICE vehicles? Or, would the whole thing be too much to ask for?

unless it is set up as a hybrid with the engine cycling on and off like conventional hybrids, fuel efficiency would be worse than just ICE drive. You don't get something for nothing, running any ICE engine constantly to turn a generator to run electric motors is overall going to be less fuel efficient than ICE and transmission along. Diesel electric trains/boats etc. sacrifice max fuel economy for the ability to better control and start the train etc. not for max fuel efficiency.

And even in the senerio above, in town fuel economy could improve significantly with regenerative braking, without that to recovery kenetic energy fuel economy would suffer.