Sooner or later, your fleet will be operating hybrid trucks. It's inevitable, given the current combination of high fuel prices and public concern for the environment.
For some, it will be a matter of image. You'll want to be seen as concerned citizens in your communities, doing what is right for the environment. It's also a marketing aid, enhancing your image among customers–government, hospitals, power plants and the like–who show their own concerns by choosing concerned vendors.
That is the basis for the EPA's Smartway program. It encourages and recognizes fleets whose owners demonstrate their concern for the environment by buying and using fuel-efficient, less-polluting vehicles and doing business with those that do. In a growing number of cities, individuals driving hybrids can use HOV (high occupant vehicle) lanes on freeways and expressways.
Financial incentives, such as tax credits and development grants, may be available to lessen the burden of acquiring new technologies. Check with your state and local governments for tax-based incentives, and search the Internet for grants and other incentives. Diesel prices above $4.50/gallon make payback for the added cost of hybrid equipment short and attractive.
The term, “hybrid,” comes from biology, when two strains of plants were combined to improve a breed. As I drive past the Midwest cornfields, I see signs for hybrid corn.Gasoline-electric hybrids
Just as corn is bred to provide the best characteristics of each parent strain—yield-per-acre and pest-resistance, for example—a hybrid vehicle combines two technologies to get each one's advantages. Gasoline-electric is most common, combining available power of an internal combustion with energy efficiency and emissions-free operation of an electric motor. In commercial applications, diesel is more energy-efficient.
For frequent stop-and-go driving, diesel-hydraulic hybrids are being developed. Instead of using only service brakes to slow and stop, they convert the truck's kinetic energy into hydraulic pressure stored in a tank. Pressure is released to turn hydraulic motors to assist acceleration, relieving the burden on the diesel engine and reusing energy normally lost as heat from the brakes.
All hybrid systems combine power sources for acceleration and use hydraulic or electric motors for regenerative braking. The reuse of braking forces is why hybrid vehicles of all sizes and types often get better fuel economy in cities than on highways.
General Motors' full-size hybrid pickups, the Silverado and Sierra, and the SUVs built on the same platforms, the Tahoe and Yukon, get similar city and highway mileage, according to EPA estimates. They may be among the first a concrete producer might bring into its fleet. They have the same general configuration and dimensions as the conventional vehicles. But towing capacity and payload are reduced, most likely to avoid overstressing the electric motor that is inside the transmission housing.