Vellum Venom Vignette: Flattened Fenders and Air Curtains

Mike writes:

Sajeev,

I have noticed something on newer cars, and it’s been bothering me for awhile now. Perhaps you, with your deity-like omniscience (and access to inside information) will be able to provide some clarity.

As you can see from the picture below, a new Toyota has this vertical flat area around the wheels. And it’s not just this particular model of car — nearly every modern car I see on the road today has a similar design feature, though they vary in the width of the flat area around the wheel arch. Contrast this the Clinton-era Toyo at the bottom, where the body lines follow a graceful curve all the way to the fender opening.

To my eye, the wheel arch flatness looks terrible. Are every automaker’s designers on the same drugs, or is this done for an actual reason — i.e, aerodynamics, or possibly to make the wheels appear larger (another trend which befuddles me)?

Looking forward to your reply, thank you!

Sajeev answers:

Access to inside information in the car design biz? Deity-like omniscience? Hardly. I contacted two experts in aerodynamics and neither responded. Even worse, one is a longtime family friend.

Aesthetically speaking: I agree. The flattened fender arches add an unnecessarily complex or flow-killing stylistic element to a vehicle’s bodyside.

Realistically speaking: The hard transition provides an aero benefit I cannot independently verify. I reckon it reduces drag and/or turbulence around the wheels, especially when adding air curtains. The two might combine to “clean up” (technical term) airflow around the front wheels. Which implies your ride gets quieter and more fuel efficient — not just for fancy BMWs, but also for the Ford F-150 and Mustang.

Which begs the question, how much does this really help? Bullet-nosed faces of the 1990s are history and we still have pedestrian-friendly fronts with extensive amounts of frontal area. Perhaps that’s why air curtains are necessary: every little bit helps.

If you’re a Car Design Wonk, please chime in below or drop me an email.

[Image: BMW, the OP, Ford]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.