Hybrids Cut Pollutants, Gain Governmental Backing
Although hybrids will pay their way through savings in fuel and brake linings, they also cut exhaust emissions substantially, say suppliers and fleets. This has gained the industry some friends in government and environmentalist groups, which can result in further payoffs.
Local and state reimbursement programs can help fleets test and buy hybrids and alternative-fuel vehicles. And the Internal Revenue Service has approved special tax deductions for purchase of Clean Fuel vehicles, said Bashar Zeitoon of the National Alliance for Environmental Innovation, which has been working with FedEx Express on its hybrid truck project. Funding programs pay varying amounts for purchase and sometimes retrofitting of commercial trucks in New York City, Washington, D.C., California, Maryland and Texas.
FedEx's tests show the Eaton diesel-electric hybrid system reduces fuel use by 45% and cuts pollutants by 60 to 100%, said Sid Gooch, the fleet's managing director, in a briefing to the Hybrid Truck Users Forum. Oxides of nitrogen, or NOx, and particulates — two principal targets of recent anti-emissions regulations — were down by 75% and 90%, respectively.
The comparisons are with a base van's mechanically controlled six-cylinder Cummins ISB, Gooch said. The hybrid has a four-cylinder Mercedes-Benz 904 with electronic controls and a particulate trap, which alone are responsible for some of the emissions reduction; the rest comes from recycling of braking energy, allowing the engine to idle or loaf and therefore spew less exhaust.
Last fall Solectria Corp. sent its "Super 7" diesel-electric hybrid on a cross-country tour that covered 8,500 miles. Engineers documented a reduction of 20% in NOx, 68% in carbon monoxide and 17% in carbon dioxide, said Dean McGrew, business development manager. The truck is a Kenworth T300 with a 220-hp Cummins ISC driving through a modified Eaton Fuller AutoShift automated mechanical transmission (see October HDT).
Hybrid operation also contributed to fuel economy improvements of 44% in stop-and-start operations and probably 15% in on-highway driving. The AutoShift alone is 10% more economical than an Allison automatic "right off the bat," McGrew said.
