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Old 06-16-2016, 04:13 PM   #1 (permalink)
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Stricter EPA testing for 2017 model year - be careful making comparisons

The EPA has introduced stricter fuel economy testing methods, starting with the 2017 model year.

The changes apply to coastdown testing to determine a vehicle's aerodynamic and mechanical resistance -- values which are then fed into the chassis dynamometers used during the actual laboratory fuel economy & emissions tests.

Remember how a few automakers got in trouble in the past few years for using "erroneous" (haha) road load values which under-reported aero/mechanical drag and therefore inflated their fuel economy ratings vs. real world results? Hyundai, for example. The same thing has been going on recently in Japan with Suzuki and Mitsubishi both getting in crap for gaming road load values for their government's tests.

The takeaway:

Keep these changes in mind when comparing the EPA ratings of 2017 vehicles to previous years. They're not 100% apples-to-apples.

Even a vehicle that carries over basically unchanged between 2016 and 2017 will likely have a lower MPG rating, as these examples show:

Not surprisingly, most of the changes affect the highway rating (except for, interestingly, the Ford Fusion hybrid). However, the differences -- 1 MPG US in each case -- are small enough they may not change the vehicle's overall or "combined" rating (except for the Camry, which drops by 1 MPG).

But in the cut-throat world of marketing, where 1 MPG may make the difference between being able to trumpet "best in class" or not, keep your skeptical eyes open.

More info:

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