Aerodynamics, Slowing Down Save Big Dollars on Fuel
Operators of construction trucks rarely consider aerodynamics, especially if their vehicles run locally, with lots of stopping and starting and at low average speeds. But aerodynamics will affect trucks run steadily on freeways and open highways.
Owner-operator Skip Becker began saving money as soon as he bought a smooth-sided Genesis end-dump trailer from East Manufacturing in August 2002. It saved enough in fuel that he paid off the trailer's $6,000 to $7,000 premium in about eight months. Continued savings made the monthly payments on the trailer.
Compared to his old rib-sided trailer, Becker saw an improvement of a little more than 0.5 mpg with the 34-foot Genesis, raising the average turned in by his Caterpillar 550-powered '97 Peterbilt 379 from about 5.1 mpg to 5.8. “At a half a mile per gallon, you're talking $900 a month” in saved fuel, he says. That boils down to $34 a day in savings at today's prices.
Becker's trailer rolls on four wide-base single tires, Michelin 425/65R22.5s, which cut rolling resistence and weigh about 700 pounds less than eight regular-size tires. He also fitted the Genesis with a Tarpco motorized tarp which smooths air flow over the trailer's top, though its main purpose is to prevent grainy loads from blowing out. He deploys the tarp even when running empty. Becker operates locally, but he runs 500 miles a day within a 100-mile radius of the Youngstown, Ohio, area.
Genesis' sides are made of patented hollow panels, says Charlie Wells, East's director of dump-trailer products. Panels are aluminum alloy extruded into 2x10-inch rectangles, which are stacked vertically and welded together. The walls then are essentially double-sided with internal ribs.
Phillip Goyne, Yuma, Ariz., is also on a quest for better fuel economy. He pulls a Clement end-dump trailer hauling decorative rock from a quarry near home to Phoenix, and the highway running maximizes the benefits of the 37-foot trailer's smooth sides. He pulls it with a Peterbilt 385, a lightweight aero-designed tractor with a 410-horsepower Cummins ISM, which saves about 600 pounds over an ISX. It runs through an Eaton 10-speed with an overdrive 10th gear, which keeps revs low at cruising speeds.
Goyne cut his speed from 77 mph to 65. “That uses up your log time, but getting 1 mile per gallon more (from 4.5 to 5.5 mpg) is worth it,” he says. “The time lost is not as bad as I thought it was. [I make] one trip per day, so there's no revenue loss. I'm trying to get to 6 mpg. If I can save $2,000 a month in fuel, that would keep me in the game, keep me able to own my own truck.”
Owner-operator Skip Becker says his smooth-sided East Genesis end-dump with its wide-base single tires saves at least a half a mile per gallon, enough to pay for itself.
Kenworth and Sterling offer daycab truck-tractors powered by Cummins-Westport engines that burn liquified or compressed natural gas, and Peterbilt will have one available later this year.
Natural gas is subsidized to varying degrees by federal and state authorities. Federal tax rebates of up to $32,000 can be had for buying a truck that burns natural gas and other alternative fuels (for a list of qualifying trucks and cars, go to www.irs.gov and type “QAFMV” into the search box in the upper right corner). Buyers of hybrid-drive trucks and cars can also qualify for tax rebates.
Production and distribution of biodiesel is steadily expanding, and on-road tests are showing the fuel has several benefits. The National Biodiesel Board says production has climbed from 250 million gallons annually in 2001 to an expected 600 million gallons this year. As of late August, there were 177 biofuel plants across the United States, and almost half of them are certified by an industry group.
Supply now is greater than demand, perhaps partly because biodiesel got off to a shaky start nearly three years ago. The problem was traced to biodiesel's tendency to act as a solvent, which cleans out a truck's fuel system and sends accumulated crud to fuel filters. Another problem was lack of consistent quality in then-available fuels. The new standards should help.
Carrying extra filters and changing them as needed, although a pain in the neck for drivers, kept engines running and, when fuel tanks and lines had been fully scrubbed, operating problems in individual trucks disappeared.
Meanwhile, drawing up of industry quality standards should boost the fuel's performance in diesel engines and its acceptance by customers, proponents feel. The American Society for Testing Materials has established standards for pure biofuel, which can be made from crops or animal fats, and more recently for biodiesel blends, which usually range from 2 percent (B2) to 20 percent (B20) as mixed with petroleum diesel.
Biodiesel's benefits, according to the board, includes restoration of lubricity lost when most sulfur is removed to make ULSD; reduced exhaust emissions, which has been proven in industry tests; and an increase of domestic fuel production which can displace imported oil. An on-going test of over-the-road tractors running on B20 in the Midwest further shows that the fuel's average Cetane number — a measure of cold-weather starting ability — is 1.8 points higher than that of straight petrol diesel, and cold-flow ability is the same for both.
However, energy content, measured in British thermal units, is 2.7 percent lower with B20. Thus B20 has delivered 1 to 2 percent less tank mileage for tractors using it in the test. Other experience shows extra filters might be needed, and the limit for storing biodiesel is about six months.
State and federal subsidies encourage use of biodiesel. It is subsidized in 16 states (Arkansas, Delaware, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maine, Maryland, Missouri, Mississippi, Montana, North Dakota, Oklahoma, South Dakota, and Washington) through incentives and tax rebates; most of these go to producers. A federal subsidy amounting to $264 per cubic meter has resulted in “dumping” of American-made biofuel into Europe at artificially low prices, the European Biodiesel Board has charged. Its members can't compete, and officials say they'll file a formal complaint with the World Trade Organization.
The political factor weighs heavily within the States. Although subsidies in various forms help make a business case for using alternative fuels (including ethanol in gasoline) all grants and tax rebates have expiration dates that must be extended by legislative bodies, including the U.S. Congress. It's unknown how the political climate will affect the future of fuel subsidies, but overall success of the fuels, along with active promotional and lobbying efforts by their proponents, will probably keep the subsidies alive.
