LOS ANGELES (Bloomberg) -- Consumer Reports said its tests of turbocharged cars from Ford Motor Co. and General Motors Co. didn't support the companies' claims about fuel economy and performance provided by the powertrain technology.
Tests of Ford's 2013 Fusion sedan with a 1.6-liter turbo engine by the consumer magazine found the car to be slower and less fuel-efficient than standard four-cylinder engine cars such as Toyota Motor Corp.'s Camry and Honda Motor Co.'s Accord.
While GM's Chevrolet Cruze compact with a 1.4-liter turbo engine is slightly faster than one with a standard 1.8-liter engine, the mileage is no better, Consumer Reports said.
Using the U.S. Environmental Protection Agency's methodology, the turbocharged Cruze was rated 1 mile (1.6 kilometer) per gallon better in combined city and highway driving.
"While these engines may look better on paper with impressive EPA numbers, in reality they are often slower and less fuel efficient than larger four- and six-cylinder engines," Jake Fisher, director of automotive testing for Consumer Reports, said in an e-mailed statement.
Turbochargers pump more air through an engine, increasing power. Automakers have turned to turbochargers as a way to have smaller engines without sacrificing power. The extra air has to be augmented with extra fuel, which may offset savings from smaller engines, Consumer Reports said.
GM, Ford response
Automakers are under pressure to boost vehicle efficiency to meet stricter U.S. mileage requirements and win fuel-economy bragging rights with turbo and direct-injection engines and hybrid systems.
Consumer Reports, automakers and U.S. regulators have been reviewing gaps between official fuel-efficiency tests and real world performance since Hyundai Motor Co. and Kia Motors Corp. in November said they overstated mileage test results.
The turbocharged Cruze has "better acceleration across the rpm range making for a more fun to drive car," Tom Read, a GM spokesman, said in a statement. "However, if you have a heavy foot on a turbocharged engine, you're not necessarily going to see a lot of fuel economy benefits." Mileage, he said, "is really dependent on how you drive."
Consumer Reports in December said Ford's two newest hybrid models, the Fusion and C-Max hybrids, fell 17 percent to 21 percent short of the EPA rating of 47 mpg in the magazine's tests.
"We cannot answer for how Consumer Reports tested the Fusion, but its findings are not consistent with our internal and external feedback," said Wes Sherwood, a Ford spokesman. "Those show that EcoBoost vehicles lead in customer satisfaction for fuel economy across segments -- including surveys by J.D. Power'' & Associates.
Turbo engines in the BMW 328i sedan and X3 SUV were more fuel-efficient than non-turbo versions, Consumer Reports said.