AAA Colorado ~ EnCompass Magazine

Not surprisingly, public awareness of hybrid automobiles has increased in direct proportion to rising gasoline prices. Most consumers think of a hybrid vehicle as a car or truck that teams a gasoline engine with an electric motor in order to provide better-than-average fuel economy. While that definition is generally true, maximizing miles per gallon is only one advantage to building hybrid cars and trucks.

Automakers today use hybrid powertrains to achieve a number of different ends, not all of them tied to fuel economy.

Today's hybrid cars and trucks are scattered across a broad spectrum of usage categories that include fuel economy, practical transportation, top-of-the-line performance, and mobile utility. They all offer improved fuel economy, but the real news is that they go beyond fuel efficiency and use hybrid technology to offer vehicle capabilities that were impossible just a few years ago. Hybrid vehicles are not created equal, but for consumers that is a very good thing.

Following are three categories that are based on the manner in which the gasoline engine and electric motor work together to power the vehicle.

Full hybrids - A vehicle whose wheels may be driven by the electric motor only, the gasoline engine only, or both working together in tandem. Full hybrids also employ energy-saving features such as an idle stop system to shut down the gasoline engine when the vehicle is not moving, a regenerative braking system to recharge the battery pack during deceleration, and an electronically controlled, continuously variable automatic transmission (CVT) to ensure optimum gearing for any situation. A sophisticated electronic control unit continually monitors and adjusts every part of the powertrain to maintain optimum efficiency.
Mild Hybrids - A vehicle in which an electric motor supplements the gasoline engine's power during high-load conditions, but the automobile is never powered by the electric motor alone. Although the gasoline engine is shut down at stops to conserve fuel, it always provides power when the vehicle is on the move. Like full hybrids, these models employ regenerative braking and a continuously variable automatic transmission to help maximize efficiency. However, several of these cars can also be equipped with a manual transmission.
Pseudo Hybrids - A vehicle that contains many components of a hybrid powertrain but does not use an electric motor to actually propel the vehicle. A pseudo hybrid is powered exclusively by its gasoline engine, which employs an engine idle stop system to achieve a small gain in fuel efficiency.

Ultra-low sulfur diesel offers a cleaner fuel alternative

Because of new EPA regulations, consumers will begin seeing a cleaner transportation fuel in the marketplace.

Called ultra-low sulfur diesel (ULSD), this new fuel will significantly reduce the sulfur content in diesel engines, thus having a positive impact on the environment. The transition to ULSD fuel began June 1, 2006, for highway diesel and will start in 2007 for locomotives, marine and non-road equipment.

The new ULSD fuel enables the introduction of cleaner-burning diesel engines and vehicles with new emission control technologies for the 2007 model year. It also will generate significant air-quality improvements. Annual emission reductions will be equivalent to removing the pollution from more than 90% of today's trucks and buses, when the current heavy-duty vehicle fleet has been completely replaced in 2030. As an additional environmental benefit, ULSD fuel will enable diesel-powered passenger cars and light trucks to meet the same emissions standards as gasoline-powered vehicles.

Because diesel engines have long been perceived as noisy and dirty, they have not successfully penetrated the U.S. market. That may change as a result of the new requirements, since in addition to being the most fuel-efficient energy-conversion devices in production today, modern diesel engines offer high fuel efficiency, low noise and exhaust levels, and improved drivability. New smaller diesel-powered vehicles combined with the reduced sulfur content standard may therefore become more attractive to U.S. consumers.

Consumers who want to learn more about ULSD should visit the website of the Clean Diesel Fuel Alliance at www.clean-diesel.org.