2011 Chevrolet Cruze: Informal Fuel Economy Test
June 02, 2011
General Motors conducted an informal fuel-economy test recently, with two Chevrolet Cruzes as the test vehicles. While not as extensive as our Fuel Sipper Smackdown, this test did highlight how different driving styles can affect a car's fuel economy.
GM fuel-economy engineers Ann Wenzlick and Beth Nunning drove identical Chevrolet Cruze LTs. The car has EPA ratings of 24 mpg city and 36 mpg highway. They drove the cars on a 20-minute route that included city and highway driving as a stop for coffee. Their results showed that taking care of small details can potentially save drivers as much as $100 a month at the pump.
The test results showed that Wenzlick averaged 37 miles per gallon using efficient driving habits. Nunning drove less efficiently and managed only 21 miles per gallon. Though the test took place for just 20 minutes, GM projected that Nunning would get 250 fewer miles per tank of gas, while Wenzlick would save $100 a month -- or $1,200 a year -- assuming 15,000 miles and $4 a gallon for gas.
As you'll see in the video below, they used the in-car fuel economy gauges for this test, so take these numbers with a grain of salt. But the fact remains: Driving styles have a real impact on your fuel consumption. And while this may not be news to some people, not a day goes by without me seeing someone driving without regard to fuel economy. If I can make one person more aware of his driving habits, I've done my good deed for the day.
Here are a few fuel saving tips from GM. Let us know if any of these work for you.
5 Driving Tips to Save at the Pump
Here are five things Ann Wenzlick did to drive more efficiently in her Cruze:
1. Get out of the drive-through lane.
"While Beth waited in the drive-thru with her car running, I shut off the engine and went inside for my morning coffee. Idling for 15 minutes burns through an average of a quarter of a gallon -- adding another $1 to the cost of your latte."
2. Take it easy
"In the city, I accelerated smoothly while Beth demonstrated one of the most common mistakes we see on the road: Jumping on the gas at every light, only to hit the brakes as she caught up with the traffic ahead. Such aggressive driving isn't going to get you home any faster, while driving smoothly can improve your mileage by 20 percent."
3. Driving 70, not 80.
"On the highway, I drove 70, compared to Beths 80. Again, a 10-mph difference likely wont add much time to your daily commute, but it will save you up to four miles per gallon on the highway."
4. Use cruise control
"I tried to maintain a constant speed during our drive, while Beths fluctuated with traffic. Try using cruise control when possible, and maintaining a constant speed over time, which is much more efficient than speeding up and slowing down over and over again."
5. Roll up the windows
"One of the most common questions we get is 'Is it better to drive with the A/C on, or off?' At slower speeds, turning off the air conditioning can save you a little, but I always roll up the windows on the highway. Beth was driving with her windows down, and the increased air pressure acted like a parachute trying to slow her down -- consuming much more energy than air conditioning ever will."
5 Vehicle Mistakes That Hurt MPG:
Here are things that contributed to Beth Nunnings poor fuel economy:
1. Low tire pressure
"All four tires on my car were five pounds under their recommended air pressure. That's not enough to change how the Cruze drives, but it does make the engine work much harder to turn the wheels. Check your tires at least once a month, as a tire that is 10 pounds under pressure can cut your fuel efficiency by more than 3 percent."
2. Using roof ornaments
"To show support for my Detroit Tigers, I put up window flags on my Cruze for every home game. But, when the boys hit the road, the flags will come down." At highway speeds, up to a third of your fuel is used to overcome wind resistance, so even small changes to your vehicle's aerodynamics will have a big impact in fuel economy.
3. Carrying extra junk in the trunk
"I had six bags of water-softener salt in the trunk I bought on sale at the hardware store. But, according to EPA estimates, every 100 pounds of weight can reduce fuel economy by 2 percent. While I saved at the checkout, that 240 pounds of salt added almost 5 percent to my fuel costs for the trip."
4. Ignoring the "check engine" light
"I called OnStar to run a remote diagnostics check on my Cruze, because the check engine light was on. Turns out the light was on because the gas cap was loose. But, more serious engine problems can cut your fuel economy by up to 40 percent."
5. Not bundling errands
"An engine at operating temperature is up to 50 percent more efficient than a cold engine. So, when possible, its much better to run five errands in an afternoon, than running one errand every day of the week."
Ron Montoya, Consumer Advice Associate @ 10,611 miles