[adrianmonk]

You do, but at least repair costs should be low because typically you won't put very many miles on that engine.

Suppose 90% of your miles are electric. After you've put 250K miles (400K km) on the car, you've only got 25K miles (40K km) on the engine. Rarely do you have significant engine trouble at that mileage.

Also, the engine design can probably be simplified if it's just acting as a generator. You don't need a turbo to provide extra bursts of power. Nor things like variable valve timing for good performance across a wide range of RPMs. Maybe you could even use an air-cooled engine like old VW Beetles and Porsches.

[bonton89]

I wish they'd just sell/rent little trailers with a charging engine on them you could take on long trips.

[jtriangle]

I know that tesla's won't allow you to drive while charging the car. It throws an error if it's plugged in, so, that's a no-go without significant hackery.

That said, they certainly have tow-behind generators, and they're certainly available for rent, it's just without modification you'd have to stop in order to charge. I've seen people with a model X doing exactly this out in the desert. Seemed to be an ok solution honestly, because they were camping and had genset power for camping needs, assuming of course that the whole electricity while camping thing is something you're into.