If you're reeling from the price of gas, this could put you over the edge.
A Consumer Reports' investigation found most cars deliver significantly fewer miles per gallon than the government and car makers claim.
Call for Action reporter Betty Sexton has details.
When shopping for a new car, the gas mileage is a top priority these days.
It's got to be real important. It's almost as much as the cost of the car.
Fuel efficiency is very important to me. That's why I bought a smaller car.
Automakers' mileage predictions are based on lab tests like these done by the environmental protection agency. Cars are strapped onto a machine called a dynamometer. It turns the front wheels, while a computer directs the driver to speed up and slow down.
Consumer Reports just analyzed the fuel economy data of every vehicle it's tested in the last five years. Kim Kleman says this analysis reveals the mileage for 90 percent of the vehicles is overstated.
The EPA tests don't correspond to the way most of us drive. Their tests represent driving on a 75 degree day on a road with no curves or no hills, which is ideal for maximum fuel economy.
And the EPA tests haven't changed in 30 years, so they don't take into account today's driving conditions. There's a lot more congestion, idling in traffic, and widespread use of air conditioning.
Consumer Reports runs its own fuel economy tests. The engineers say these tests, done outdoors, give a much more accurate assessment of the actual mileage you'll get from a car.
Consumer Reports' tests often turn up results that are substantially different from the EPA's, especially for stop and go city driving. For instance, with this jeep liberty diesel, the EPA says you'll get 22 miles per gallon, but Consumer Reports found you'll get just half that, 11 miles per gallon.
With this Chrysler 300 C, the EPA says you'll get 17 miles per gallon, but Consumer Reports' tests get only 10.
As for this Honda Odyssey minivan, the EPA gets 20 miles per gallon, Consumer Reports gets just 12.
And the difference Consumer Reports turned up with hybrids in city driving are even greater. With the Honda Civic, the EPAp says it gets 48 miles per gallon, Consumer Reports gets just 26.
Newer cars tend to overstate the mileage more than older ones. So the discrepancy between what you're promised and what you're getting seems to be growing.
And Consumer Reports says with skyrocketing gas prices, that's a trend that's more troubling than ever.