Over the past couple of years, I've noticed a great improvement in turbocharger performance on factory vehicles.

Subaru, Volkswagen, Porsche and Saab all regularly put out vehicles with turbochargers installed, and every year the performance is smoother. The only current American car I'm aware of that runs a turbo from the factory is the Dodge SRT4, and I believe that the engine is sourced from Mitsubishi. Chevrolet's Cobalt SS Supercharged runs with a supercharger (hence the name).

The big difference, in case you don't know, between a supercharger and a turbocharger is the source of power -- a supercharger is driven by a belt from the engine, just like an alternator is driven; a turbocharger is driven by exhaust gases. According to HowStuffWorks, a turbocharger is more efficient than a supercharger, but it causes back pressure and tends to provide less boost until the engine is running at higher RPMs. Turbochargers tend to work better on engines that hit their power peaks at high RPMs.

The driving experience with a turbocharged engine can be exhilarating, but a little hairy. There's almost always a spike in power when the turbo kicks in to operation. Driving a supercharged car is always a thrill from the bottom of the tach all the way to redline.

Both systems would play havoc with my driver's license, I'm sure. Maybe it's a good thing that I've never owned a turbo- or supercharged car.