Just a thought. Why aren't there diesel-electric cars?

10 Feb 2016

I’m from a railway family and I can tell you that the diesel engine in locomotives doesn’t turn the wheels, it turns a generator to power the electric traction motors to turn the wheels, this is known as diesel-electric. The diesel engine isn’t mechanically connected to the driving wheels at all. I’ve heard of buses using a diesel-electric set-up, but why haven’t we seen cars use this? Electric motors have their advantage in day to day driving.

Comments

Hydrogen fuel cell is similar to diesel-electric. Maybe it’s the size/weight of the generator.

it give to much polucion to get bennefit from the goverment

I can only guess why, I think that this setup in a train is good because of the weight that needs to be pulled, you don’t have that much weight in a car, the diesel-electric system causes a lot of weight itself and there are a lot of parts that need to be installed somewhere, this makes the car vulnerable to technical failure and also quite expensive to produce.
I don’t know if I’m right, but that would be my explanation.

This in essentially what the Fisker Karma is, but that uses a petrol engine to power the generator, so I guess you’d call that a petrol-electric.

Fisker tried to do that, using a gas motor running on flex fuels to power electric motors. Specifically referring to diesels I’m not too sure of a reason apart from the fact that it wouldn’t sound great to have a diesel engine that sounds like a generator in a car.

They do exist.

But in all seriousness, I can’t fathom why manufacturers haven’t got to it either. Diesel engines are more efficient than their petrol counterparts, and electrification has done wonders to increase the gas mileage of cars like the Chevy Volt. In theory, the two should be like chocolate and peanut butter. A marriage made in heaven. So why haven’t any carmakers (James May excluded) put this combination on the road yet?

Check out the V60 D6. Thats a diesel plug-in hybrid. Peugeot also has one.

yes but a diesel electric is when the diesel engine is , in effect, a generator for the electric engine. the electric engine cannot run without the diesel ‘generator’ powering it. i stand to be corrected though.

Fisker Karma works exactly like that. the problem is that you waste a lot of energy.

Would I be right in saying the new XC90 has a diesel hybrid variant, I know some other Volvos do. I’m guessing there isn’t as many due to the fact they need to warn up and what not, petrols are quicker to get going…

They havent really been used in cars due to weight and space. diesel engines weigh alot more than petrol engines and electric motors arent exactly light so it would just end up very heavy. which then would make it less efficient. so defeat the object of creating this set up. i guess but that is just my own thoughts on it.