Originally Posted by dtownfb
My question is how does Chevy, Ram, Toyota, etc determine the fuel mileage for their trucks? Is there an industry standard?
The testing criteria is determined by the EPA. Because the test is run in a lab on a dyno, the vehicle is sitting still. As such, wind load and road resistance is not present. To account for this, engineers calculate the two variables and essentially program the dyno to replicate the increased load on the vehicle.
The suit is assenting that Ford fudged those variables in their favor, making the testing environment not match real world conditions. This would result in better fuel economy and a better test outcome.
Everybody does it the same way and submits all their testing and results to the EPA for review and certification. At the very least, if everyone follows the criteria, it's a fair comparison of one vehicle to another.
The suit isn't alleging that anything is wrong with the test itself, how realistic it is, or how closely it matches real world driving. It's alleging that Ford stacked the deck in it's favor, which isn't fair to customers or competitors.