Jay Leno testing one briefly. It’s a plugin series hybrid, the gasoline engine doesn’t “help” the acceleration like in the parallel hybrid cars produced so far, and it’s supposed to come out in 2010. But a 1.4 liter gasoline engine seems awfully big and probably increases weight of the vehicle – which is a lot, about 1700 kg. The car is so heavy because of the electric stuff though that maybe the large gas engine is necessary as well.
Why does 1.4 liters seem a lot? Well, since it’s a series hybrid, you only need to produce the average power, the batteries handle the bumps. Typically cars use only a fraction of their available peak power. But in a series hybrid the gas engine can be tuned to being small and running at pretty high constant RPM to make it light and efficient as well. Many ordinary gasoline cars of 1000+ kg mass have 1.4 liter engines over here, hence it looks like a huge displacement for a series hybrid.