How is the vehicle fuel economy (mpg) measured in the US ?
How is vehicle fuel economy (mpg) measured in the US ? Ever wonder how those city / highway MPG (miles per gallon) numbers on the sticker come from ? Here you go. The US EPA requires vehicle fuel consumption to be measured using lab chassis dynamometer testing. A representative vehicle is run over five test cycles, listed below along with the respective ambient temperatures: FTP-75 at 75 F: Represents city driving. Includes 3 measurements called bags (because the emissions are collected in bags !), with the first bag after a cold start (>12 hour overnight “soak”) and a hot start with engine off for only 10 min. HFET at 75 F: Highway fuel economy test US06 at 75 F: High speed and aggressive urban driving SC03 at 95 F: Represents the impact of air conditioner use at high temperatures Cold FTP at 20 F : Impact of cold ambient temperatures The above tests measure the fuel consumption over a wide range of driving conditions and provide a realistic assessment of on-road performance to the consumer. Note that till a few years back, only two cycles were used to measure the fuel economy: FTP-75 and HFET. Miles per gallon numbers from
