EVs Are Great Around Town, But.......
 

I wonder how hard it would be to attach a diesel powered pusher trailer for highway trips? EV around town, without the weight of the ICE and, with the trailer attached, long range diesel for extended trips. I know I could haul a generator to feed the EV battery, but with the extra step of mechanical to electricity, there is an extra loss of efficiency. Better to drive an axle directly from the engine. The trailer hookup could be rigid, side to side, with hydraulic cylinders on each side to tilt the trailer for turns.

Forget the generator idea. All mass produced electric vehicles are immobilized when the charger is plugged in.
A mass production EV would have to be modified and/or reprogrammed to allow for charging while moving.

Easier to just ask to borrow my (or your neighbor, friend, uncle) Prius.

WOW! Thanks! I see the idea is not new. I'm thinking of a pusher-trailer, not a generator-trailer.

I already have the Prius, but it's not a plug in, and even those won't go the hundreds of miles without a plug in every couple of dozen.

Get a plug in hybrid.
The 20 to 30 Mike range most of them have should eliminate almost all gasoline usage.
Not like there is much weight difference between an EV and a hybrid.

There's no point in forcing an EV to go long distances. It's not the right tool for the job. People can do it if they want, but it's their time wasted.

I think you are missing the point. I'd like a plug in EV, like a Nissan Leaf, but I don't see the need to haul the ICE around town. I'm looking for a solution that allows me to keep the ICE in the garage until needed for highway trips. Thus, the pusher trailer. Anything with an ICE and transmission with enough HP to push the car at 75. A double mounted hitch with, maybe, one drive wheel. Maybe, even a puller trailer.

Leave the prius parked and get a leaf.
When it gets cold you don't really want to drive the leaf. Trust me.