For as long as electronic cars don't rule the world, I'm a fan of Transonic Combustion's patented way to make gasoline-drinking cars more efficient. And these people mean business: they claim a quite respectable improvement of around 50% more performance for your fuel! Their test car, with a usage of approximately 3,8 l./100 km, outperforms Toyota's Prius, with ~4,4 l./100 km.

The secret? Heating up and pressurizing the gasoline before injecting it in the engine's combustion chamber. But warming it up just a tiny bit isn't going to cut it, the gasoline has to be put into supercritical state; at a temperature and pressure-level above its critical point which makes the gas behave like something in between a gas and a liquid. This 'supercritical gasoline' makes for very clean and efficient combustion, so you don't need to burn as much gas as you would with the gasoline in its normal state (below its critical point).

For more information, head on to Transonic Combustion's website. I say let's rig our cars with this stuff, it looks fine to me! :D
Via Technology Review.