Hybrid vehicles are the latest addition to the eco-friendly army of automobiles with one distinct advantage over all other types -- they're AVAILABLE! Two companies, Honda and Toyota, are currently selling their own unique rendition of hybrid vehicle. The Toyota hybrid (on the left) is called the Prius. It is a four door family sedan capable of a gas mileage of about 54 city, 48 hwy. It is rated as a SULEV (see chart below), thus giving it the best emissions rating of any gasoline car on the road today. The Honda Insight (below right) is a sporty little two door hybrid boasting the best gas mileage of any gas powered car made, 70 hwy, 61 city! It's emissions rating is a not-so-shabby ULEV (although the new model sporting a Continously Variable Transmission qualifies as a SULEV, albeit the mileage is less: 58 hwy, 54 city). Both vehicles cost about $20,000 retail and are available nationwide (although there is quite a waiting list I hear). Ford is planning on releasing their first hybrid vehicle, the Escape SUV, in 2003 (see picture below). The Escape will be using a powertrain similar to the Prius (Ford has contracted to buy powertrains from Toyota) and will get about 40 mpg as well as the super-clean SULEV rating. The Escape will be the first hybrid SUV on the market and definitely will set the fuel efficiency benchmark for all SUV's to beat!

What are these strange fuel efficient gifts from heaven? They certainly have come just at the right time as gas prices are projected to reach $3/gal. by the end of 2001! A hybrid vehicle is a vehicle that uses both a gasoline engine and an electric motor/battery pack (although battery/super capacitor combinations are now being sought as cost effective replacements to larger battery packs). You see, gasoline engines are terribly inefficient at low and high rpm's. A gas engine is happiest when at a mid-range constant rpm. Conversely, an electric motor has an extremely wide range of efficient operation and can produce high torque almost uniformly across its rpm range. When you unite these two technologies, what you end up with is an extremely efficiently operating machine with all the power of a gas engine plus nearly all the benefits of an electric vehicle (quiet operation, reduced emissions) without all the drawbacks normally associated with electric vehicles (short range, long recharge times) and gas engines (dirty, noisy, and wasteful). This means a hybrid vehicle is refueled with gasoline and never has to be plugged in to be recharged. It also means you can go 500 - 600 miles on a regular tank of gas! The whole idea of the hybrid was to eak out every bit of efficiency by eliminating the infamous drawbacks of heat engines (a heat engine, or Carnot cycle engine, has a maximum theoretical efficiency of about 40%; an electric motor gets about 90%). Under this theory, the electric motor takes care of the sudden bursts of power needed for acceleration, while the gas motor either supplies a constant torque to the wheels or generates power for the batteries. Further, hybrid vehicles can take advantage of regenerative braking (using the electric motor as a generator while braking to recharge the batteries) to get back all that energy typically lost as heat in regular cars. Also, hybrids can automatically turn the gas engine off while idling in traffic, and then instantly start it up again when the gas pedal is depressed. This eliminates needless running of the motor while in traffic jams and while at stoplights, without the risk associated with turning your car off (and then not being able to restart it). There are two main categories of hybrid vehicles: series and parallel. See the diagrams below to understand their function.

Any way you slice it, hybrids are a step in the right direction. We can certainly benefit from better gas mileage and lower emissions! Hybrids are not the final answer, however, to our energy and pollution woes. Hybrids are still dependent on gasoline and they still put out noxious pollutants into our atmosphere, albeit much less than normal cars. Many automakers are seeing hybrids as a transitional technology. The technology can also be applied to fuel cell vehicles and hydrogen combustion vehicles. In either case, the zero emissions benefit of hydrogen can be accompanied by the increased range and performance of electric motors and battery storage. Some automakers are already testing prototypes of fuel cell hybrids and hydrogen/CNG combustion hybrids. The great benefit here is the decrease in the need to store large amounts of hydrogen, a main cause in the delay of fuel cell vehicle advancement. With the hybrid technology a suitable range of 300 miles per tank could easily be obtained with a modestly sized tank of compressed hydrogen. Regardless, hybrid vehicles are here today! They require no social change in driver habits and put money back into the owners' pockets immediately, not to mention they're futuristic and COOL! They should definitely be embraced and used to their fullest extent now!