How to go farther on a gallon of gas

June 25, 2013 2:27:00 PM PDT
Summer's here and that means plenty of road trips. Gas prices may be down, but your run through gas quickly when you're putting on the miles.

Consumer Reports' latest tests show how you drive and what you carry can make a big difference.

Fueling up is never a favorite stop.

"Ten years ago when I bought the car, it was about 20 bucks. Now it's 42," one person said.

"It's expensive you know. It's a lot of money," said another.

While you can't control the cost of gas, you can control how far you go on a gallon of gas.

Consumer Reports testers use this fuel meter to put several cars through their paces at 55, 65 and 75 miles per hours.

"While it may not be surprising that when you drive faster, you use more fuel. You may be surprised about how much fuel you actually use," Jake Fisher of Consumer Reports said.

Take this 4-cylinder Honda Accord LX. At 55 miles per hour it gets an impressive 50 miles per gallon. But at 65, it drops to 42 miles per gallon and going 75, it drops to 36 miles per gallon.

"We also tested the Toyota RAV4 and three versions of the Ford Fusion. Including the hybrid and we found similar results with all of them," Fisher said.

Loading your car for road trips also cuts your fuel efficiency, including adding a bike rack.

By how much? Remember the Honda Accord at 65 miles per hour getting 42 miles per gallon? With a bike rack, fuel efficiency drops to 37. Add a wind deflector, and surprisingly it drops again to 35 miles per gallon. Now add two bikes and the mileage sinks to 27 miles per gallon.

"So if you're not using your bike rack, take it off because it really is going to hurt your fuel efficiency," Fisher said.

A lighter load and a lighter foot on the pedal definitely add up to savings at the pump.

A rooftop luggage carrier can also cut your fuel efficiency. Consumer Reports says you can lose up to six miles per gallon with one of those on top of your car. So take it off if you aren't using it. And to get the best mileage possible, make sure your tires are properly inflated.