The Porsche 911 GTS Is Less Aerodynamic in the US—and Safety Is Why

The active rear wing's most slippery setting conflicts with other federal standards.
Porsche

I just got back from Spain driving the new and newly hybrid 2025 Porsche 911 Carrera GTS. Unfortunately, my impressions are embargoed until July 9 (come back then for the full review), but one amusing detail I can share now is that, here in the United States, the new 911 will be slightly less aerodynamic than it will be in the rest of the world. The reason? Safety, sort of.

Per a Porsche Cars North America spokesperson, “In Europe and other markets, [the 911 Carrera GTS Coupe’s coefficient of drag] is 0.27. For the U.S. cars, the value is 0.29, based on the fact that we do not have an Eco mode setting for the rear spoiler, due to specific brake light visibility requirements in the U.S.”

The 911 GTS comes standard with an active rear wing that adjusts itself depending “primarily on speed, but also on the charge-air temperature.” Presumably, the wing’s most slippery setting blocks the third brake light in a way that makes it non-compliant with NHTSA’s Federal Motor Vehicle Safety Standards (FMVSS), resulting in a 0.02 Cd penalty.

Porsche

It should be noted that the difference between a Cd of 0.27 and 0.29 isn’t night-and-day. According to Popular Mechanics, Cd variations of up to 5% can be recorded by the exact same car depending on the wind tunnel and testing methods being used. But it also isn’t nothing. Porsche’s own Taycan Turbo, for example, has a published Cd of 0.22, while the Tesla Model S notches a 0.24, and the jellybean-shaped Mercedes-Benz EQS outperforms them both with a 0.20 Cd. Carmakers will even brag over the relative efficiency of their exterior designs, especially when marketing EVs targeting ever-longer range.

It should also be noted that this U.S. versus rest-of-world difference in the aerodynamic properties of the Porsche 911 GTS isn’t a new development, as this discrepancy existed in the outgoing GTS, too. “Eco Mode spoiler setting was also not available on the previous generation (992.1) in our market, so this doesn’t represent a change from the car before,” the Porsche spokesperson told The Drive. Nevertheless, it’s a detail I found interesting, and one I don’t think a lot of people know about, so there you go.

If you absolutely must have the most aerodynamic 911 GTS that Porsche makes, you should probably start looking into emigrating. Or just wait for someone to jailbreak that active rear wing.

Got a tip or question for the author about the new 911 GTS? You can reach him here: chris.tsui@thedrive.com