Two things that annoy me about the EPA test is that it’s on a rolling road and thus I can assume aerodynamics don’t come into it.
@AndysComputer I think
this Car and Driver article does a really good job explaining the EPA's testing, including the "road load" factor, which, as the article notes, "encompasses aerodynamic drag, tire rolling resistance, and driveline friction." Further...
Road load is measured through coastdown tests, wherein vehicles coast—hence the name—in neutral from about 80 mph all the way down to 10 mph. The resulting data of how quickly the vehicle slows is used to calculate the three coefficients for a quadratic equation that expresses the pounds of force resisting a vehicle's forward motion at a given speed. Those coefficients define the dyno's resistance during efficiency and range testing.
So aero is a factor in the EPA's range and efficiency testing, and it was undoubtedly a significant factor in
Lucid earning an official EPA range of 520 miles for their Lucid Air Dream Edition, which features a 118 kWh battery pack (as compared to the Tesla Model S Long Range, which I believe features a 103.9 kWh battery pack and is EPA rated at 402-miles of range). You can read more about the aero work that went into Lucid achieving a 0.20 drag coefficient
in this MotorTrend article.
I'm a fan of Rivian, but they've achieved their 300+ mile range via brute force, aka adding lots and lots of batteries, which isn't a particularly sustainable approach. Certainly, the Lucid Air Dream Edition doesn't have a small battery, but I admire their emphasis on efficiency, and they do offer a model with a smaller battery, and I suspect they'll go even smaller in the future.
