Marketing and reality may often be two very different things, thus the ubiquitous “Your mileage may vary.” when it comes to automobile performance, handling, durability, and fuel economy. Thanks to various independent testing agencies, such as the Environmental Protection Agency [EPA] and Consumer Reports [CR], consumers can get a better idea of vehicle performance and fuel economy. Where the EPA and CR differ, though, is in their testing methods, specifically for fuel economy.
For the most part, the EPA relies on data from the automaker, including engine power, torque, capacity, transmission gearing, and vehicle weight to perform a series of calculations estimating fuel economy. On the other hand, CR takes actual vehicles and subjects them to real-world driving conditions, much like recently described by Edmunds.com. We know already that estimates and real-world conditions rarely match, but CR’s latest round of testing is casting some doubt on EPA’s testing methods.
In a recent round of vehicle testing, CR compared turbocharged and naturally-aspirated vehicles for performance and fuel economy. Turbocharged engines are purported to deliver big-engine performance and small-engine fuel economy. It seems to make sense on paper, which would be the EPA’s method, but real-world testing shows the turbocharged engines don’t perform as expected.
The 2013 Ford Fusion EcoBoost uses a small 1.6ℓ turbocharged i4 engine producing 173hp, while the Fusion SE uses a conventional 2.5ℓ engine. Unfortunately in real-world testing, the turbocharged model fails to perform as quickly as practically any of the new family sedans equipped with naturally-aspirated engines. Additionally, the EcoBoost’s fuel economy was lower by up to 6mpg when compared to the Nissan Altima 2.5ℓ.
Another test included two versions of the Chevy Cruze, the 1.8ℓ i4 and the 1.4ℓ turbocharged version. The turbocharged engine “feels” more powerful, but was practically identical in performance and fuel economy to the naturally-aspirated version. Why would consumers spend the extra premium on the turbocharged engines if they don’t perform as claimed? Perhaps EPA needs to revise its testing methods.