April 25, 2006

Purdue expert: Efficient driving can lessen pain at the pump

WEST LAFAYETTE, Ind. – With gas prices soaring and the summer travel season approaching, a Purdue University automotive expert says drivers can lessen the financial impact at the gas pump by driving more efficiently.

Heather L. Cooper, an assistant professor of mechanical engineering technology in Purdue's College of Technology, says even small adjustments in driving habits can make a difference in the amount of money spent on gasoline.

For example, the average family minivan is driven about 20,000 miles per year. At an average fuel economy of 20 miles per gallon, an increase of just two miles per gallon can lead to annual savings of $300 at current prices.

Cooper offers several suggestions to improve gas efficiency on those long-distance vacation treks:

• Summer driving means running the air conditioner, but do so on the recirculation setting to minimize the energy required to maintain a constant temperature. In addition, setting the air conditioner at a comfortable temperature and not adjusting it will use less fuel than turning it on and off as needed.

• Contrary to conventional wisdom, pickup trucks should drive with the tailgate up, rather than down or removed completely. A well-sealed cover or cap can improve mileage by reducing drag across the truck bed.

• For longer highway trips, lower speeds are better. When driving above 55 or 60 mph, gas mileage drops significantly.

• Whenever possible, keep the engine load fairly even and use cruise control to maintain a consistent speed, which uses less gas than repeatedly accelerating and decelerating.

• Use less expensive regular gasoline with a lower octane, as opposed to more expensive premium options (unless premium is required for your vehicle). Higher octane fuel does not provide benefits unless your engine is not working well.

• Keep tires inflated to manufacturers' specifications and make sure your vehicle is in good working order through regular maintenance.

• Do not allow the vehicle to idle for long periods. If you expect to be waiting in one place, turn off the engine.

"When driving in town, it is difficult to conserve fuel while making a lot of stops," says Cooper, a former engineer at General Motors Corp. and a researcher with the Energy Center in Purdue's Discovery Park. "People should remember that driving less also conserves energy and fuel. Try to combine errands into one or two weekly trips. Plan your trips around town in advance to minimize distances and eliminate backtracking."

Writer: Matt Holsapple, (765) 494-2073, mholsapple@purdue.edu

Source: Heather L. Cooper, (765) 494-9653, hcooper@purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

To the News Service home page