Although hybrid cars are the rage, and there are all kinds of alternative energy sources on the horizon, hybrids are cost prohibitive, usually ranging $3000 to $7000 more than the gas only version of that model. However, instead of changing fuel sources, some automotive companies have been using a new type of transmission to improve fuel economy, lower emissions, and actually make vehicles faster without adding to the sticker price.

These companies are using a continuously variable transmission (CVT) and instead of having set gear ratios (or gears), it constantly varies the gear ratios, as well as engine performance, so that they both operate at their most efficient level in any driving scenario.

Because these key components of the power train are at their peak performance at all times, fuel economy is improved by 6-8% and carbon dioxide emissions are reduced by 10%.

Although these figures may not sound impressive, the gas savings increase the highway mileage of most vehicles by 4 to 6 mpg, which adds up pretty quickly at $3/gallon.

The CVT's potential for reducing emissions is also significant. As Carlos Ghosn, CEO of Nissan Motor Company, said, achieving his goal of selling one million CVT equipped vehicles by the end of 2007 will have ?the same effect in terms of reducing CO2 emissions as selling 200,000 hybrid electric vehicles.?

Since there is no shifting between fixed gears, there is no ?shift shock? or jerking sensation, which makes them exceptionally smooth to drive. CVTs also do well in hilly terrain since there is no ?gear hunting? or bogging down on a hill, followed by a loud, violent downshift, which also contributes to its superior acceleration.

You may be wondering why this isn't in every car if it is so great. Well, every year, more vehicles in the American market add CVTs as an option, though it has happened quietly, as many people are leery of new technology, especially in cars.

The CVT is actually quite old although it is new to American automobiles. The concept was developed by Leonardo DaVinci and was first patented in the late 1800's for industrial applications. The CVT has been used in Asian and European vehicles since the 1950's, but until recently CVTs could not handle the power that American drivers demand from their cars. However, CVTs have seen widespread use in snowmobiles and Formula 500 racing where they have a reputation for extending engine life and being much easier to rebuild than either a manual or automatic step transmission.

So where can you test drive a CVT-equipped vehicle? Well you can go to dealerships selling Ford, Dodge, Audi, or Mini-Cooper, to name a few, although a Nissan dealership may be the best place to go. In order to hit their goal of one million CVT sales in 2007, they have installed CVTs in nearly every sedan in their lineup, including the best selling Altima, Maxima, and economical Versa (as a side note, Nissan has also made side curtain airbags standard in these models, improving safety and reducing insurance costs).

Although you may not have the budget for a hybrid vehicle or cannot wait for that miracle fuel to hit the market, you can take it easy on the environment, as well as your checkbook, by checking out a few cars with a CVT.