They do, but most hybrids in the USA run off gasoline. Except for diesel/electric locomotives, which are also hybrid vehicles, if BIG ONES. I suspect gasoline hybrid cars are dominant in the USA due to the early commercial success of the Prius. read more
Probably because the intention of hybrids is not so much to reduce fuel consumption - but lower emissions. read more
Volkswagen's line of TDI diesel cars has passionate fans. Now that the company is launching the 2013 VW Jetta Hybrid, it will likely gain some hybrid advocates too. But diesel and hybrid fans are very different groups, as the company's marketing surveys show. read more
The VW diesel hybrid used all manner of exotic materials to make the car a light as possible. But using less exotic materials would not only lower the price but also still provide high MPGs in the 60+ mpg category. I believe the real reason for the absences of a diesel hybrid is that car makers have concluded that first the EPA hassle with emissions plus the possibility of low sales are to blame. read more
If the hybrid car runs most of the time on electric drive, diesel is a super way go: Diesel engines really like constant speed operation. You'll top-up the batteries as needed. If the hybrid car runs most of the time by burning hydrocarbons, gasoline engines just re-start smoother. read more