Is there such a thing. They work great for locomotives. Is it a size issue? Where this only becomes practical in large scale vehicles with big weight where torque is the real need.
I have always thought that a car or possibly a truck with electric motors driving the wheels with the motors mounted outboard as iatrical parts of the hub and a diesel electric power plant and battery reserve would make a fees able and efficient platform.
Is there such a thing out there already? Or is there some problem with the system that makes it not work on the scale of cars and small trucks.
Our buses use a small Cummins diesel to run a generator and an electric motor to drive the wheels. No fancy hub motors though, just a standard rear axle with a big motor.
In reply to dean1484:
I was stopped at a light behind a Passat TDI last week, and I noticed it happened to be an SEL model. It seems VW really missed the mark by not offering it as a diesel hybrid - they could have simply badged it the TDIESEL with the "E" in green letters and probably quadrupled their sales figures. 
As I understand it, trains run diesel-electric because you'd have a crazy complicated and lossy transmission to drive all the wheels directly.
22track
New Reader
5/3/15 3:21 p.m.
Audi is going there.
http://cleantechnica.com/2014/12/17/2016-audi-q7-debuts-plug-diesel-hybrid-option/
Volvo has one in Europe.
generally diesel electrics work at best efficiency at a fixed speed. Not something that really translates well into our day to day stop and go traffic.
Not saying it can't be done.. with computer management the way it is today, almost anything is possible
I want to say that companies aren't developing it for the US market because we don't want to purchase diesel cars and trucks in the first place. We also forget about some vehicles that Europe gets. Since the Jetta TDI got better highway mpgs than the Prius back in 06, they would be great for hybrids.
http://www.caranddriver.com/reviews/2014-volkswagen-xl1-first-drive-review
This is only a concept.
http://cleantechnica.com/2015/03/12/hyundai-tucson-48v-hybrid-concept-diesel-phev-concept-showcased-geneva-motor-show/
You would still have the advantage of little transmission loss, and you would also get the benefit that you can run the diesel at constant speed. The battery reserve also means the diesel engine may only have to be 35 HP or something, but it is 35 HP continuous. The battery pack covers the temporary demands higher than that.
BTW, I believe this is exactly what the Volt does, but it does it with a gas motor.
