Drive Differently, Save Gas

NEW YORK (MarketWatch) -- With gas prices hovering near $4 a gallon you might consider taking a bus or jumping into a car pool. While these alternatives will save you money, you can take less drastic measures too: By simply changing the way you drive, you can cut your spending on fuel.

Consumer Reports suggests these four tips on how to drive more fuel-efficiently:

Minimize driving with a cold engine.
Engines run most efficiently when they're warm. In Consumer Reports' city-driving tests, making multiple short trips and starting the engine from cold reduced fuel economy for both the sedan and SUV. Engines also produce more pollution and wear faster when they're cold. To minimize cold-engine driving, avoid making a lot of separate short trips with a cold engine. Instead, combine short trips into one so that the engine stays warm.

Drive smoothly.
Avoid hard acceleration and braking whenever possible. In Consumer Reports' tests, frequent bursts of acceleration and braking reduced the Toyota Camry's mileage by 2 to 3 mile per gallon and the Mercury Mountaineer's by about 1 mpg. The harder you accelerate the more fuel you use. Unnecessarily hard braking wastes the fuel you use to get up to speed. Drive smoothly and anticipate the movement of traffic. Use your brakes as little as possible, since every time you hit them you are wasting fuel. Once up to speed on the highway, maintain a steady pace in top gear. Smooth acceleration, cornering and braking not only save fuel but also extend the life of the engine, transmission, brakes and tires.

Reduce unnecessary drag.
At highway speeds, more than 50% of engine power goes to overcoming aerodynamic drag. Don't add to that drag by carrying things on top of your vehicle when you don't have to. Consumer Reports installed a large Thule Cascade 1700 car-top carrier on its sedan and SUV. Keep in mind, however, that the effect varies, depending on the model. Driving with the carrier cut 6 mpg from the normally aerodynamic Camry, dropping it from 35 mpg to 29. It reduced the boxier Mountaineer only from 21 mpg to 20 mpg. Even driving with empty racks on the car reduces its fuel economy.

Slow down.
Aerodynamic drag exponentially increases on the highway the faster you drive. Consumer Reports tested its vehicles' fuel economy at 55, 65, and 75 mph. Driving at 75 mph instead of 65 reduced the Camry's gas mileage from 35 mpg to 30. For the Mountaineer, fuel economy fell from 21 mpg to 18. Slowing to 55 mph improved the gas mileage by similar margins: The Camry improved to 40 mpg and the Mountaineer to 24 mpg.

By Marshall Loeb