DETROIT (Bloomberg) -- Ford Motor Co., facing criticism for the fuel-economy performance of some of its models, said the U.S. Environmental Protection Agency may change its procedures for testing the mileage of hybrids.
Several of Toyota Prius hybrid models showed even bigger fuel-economy shortfalls against the EPA estimates than the Ford Fusion hybrid and C-Max hybrid when tested for mileage in city driving by Consumer Reports magazine, Raj Nair, Ford’s product development chief, said at the Deutsche Bank Global Auto Industry Conference in Detroit on Tuesday.
"They reflected a lot of differences versus the EPA label for all manufacturers," Nair said today on a Web cast of the conference. "There are a lot of factors that can introduce that type of variability" in actual fuel economy compared with EPA ratings, including speed and outside temperature, he said.
Ford's two newest hybrid models fell 17 percent to 21 percent short of the company's promise of 47 miles (76 kilometers) per gallon in tests by Consumer Reports, the Yonkers, N.Y.-based magazine reported last month in a statement. The Ford Fusion hybrid achieved 39 mpg, while the C- Max hybrid averaged 37 mpg in tests of city and highway driving, Consumer Reports said.
Hybrids can lose about 7 miles per gallon when driving at 75 miles per hour rather than 65 mph, Nair said. A difference of 30 degrees in outside temperature can cause a 5 mpg disparity. Another 5 mpg can be lost for a hybrid after 6,000 miles driven, he said.
"We continue to work closely with the EPA to determine whether the industry testing procedure needs changes for hybrid vehicle testing," Nair said.
Ford Motor Co said it is aiming for a 10 percent improvement in the quality of its touch-screen entertainment and navigation system by August as the automaker works to tackle an issue that has hurt its quality and reliability rating.
Meanwhile, Nair said MyFord Touch is the primary reason that Ford has seen a drop in its North American quality over the last two years, while quality has improved in its other global regions.
Ford reported 400 problems with its MyFord Touch system for every 1,000 vehicles in November 2012. It aims to lower that number to 360 by August.
Ford has already made inroads in boosting the quality of this system, which was introduced in 2010. In March 2012, Ford's "things-gone-wrong" rate was 500 for every 1,000 vehicles.
MyFord Touch was launched in 2010, the first of several "infotainment" systems that are important in attracting car shoppers, but automakers have struggled to create easy-to-use systems.
Last year, Consumer Reports magazine lambasted MyFord Touch as fussy and cluttered. Ford also tumbled in an annual survey of vehicle reliability due to problems with MyFord Touch.
-- Reuters contributed to this report.