GM describes 2013 Chevy Malibu ECO aerodynamic tweaks (Cd ~0.28)

[MetroMPG]

[The designers] achieved the lowest wind drag for a Chevrolet midsize car in the past 100 years.

Detail optimization removed 60 counts (0.006) from the drag coefficient, making the shape "nearly as efficient" as the Chevrolet Volt .28 Cd.

Some of the improvements, quantified:

• 11 counts: Outside rearview mirrors are specifically designed to deflect wind without “upsetting” the airflow

• 10 counts: Rounded front corners – from the bottom of the fascia up through the headlamps – help air flow smoothly along the Malibu’s body sides

• Seven counts: Shutters in the lower grill opening on select models open and close automatically to maximize aerodynamic efficiency. This increases cooling airflow to the engine under certain conditions, such as under high engine loads at low speeds, and reduces aerodynamic drag when extra cooling is not needed.

Those are 28 counts of the total, all of which result in "up to 2.5 miles per gallon more on the highway."

(NOTE: see post #18 for the rest of the modifications, quantified.)

A quote about working within government regs:

“The Malibu was my first assignment on a truly global program, so I spent a lot of time researching the different standards around the world,” said Bednarchik. “For example, smaller mirrors could improve aerodynamics further, but each global market has requirements for mirror size that must be met.

Source: Chevrolet News - United States - News

[MetroMPG]

Should I be rewarding slow, incremental improvements by regurgitating corporate press release tidbits about cars that "almost" get to .28 Cd?

I feel kind of dirty.

[winkosmosis]

Don't feel dirty. This looks a lot better than the frumpy American sedans of the 90s that drove people to SUVs

[cfg83]

MetroMPG -

Improving the aerodynamic efficiency of the new Malibu wasn’t easy. Bednarchik and Cody’s testing is detailed and exhaustive, at times requiring midnight shifts in GM’s wind tunnel in Warren, Mich. They test aero changes as small as 1 millimeter at a time, and they may test one part of the Malibu multiple times until they are satisfied they’ve achieved the most efficiency possible.

One mm at a time? I'll stick with one M&M at a time.

CarloSW2

[gone-ot]

...as the beggar said: "...well, I'm ALMOST rich..."

...l'd like to *see* those 1mm adjustments! Made with a sledge hammer on the metal stamped body panels?

[jime57]

Well, I've been as hard or harder than most on GM, and particular their use of numbers, but lets give them a little credit when due. It is a decent looking car and they are actually concentrating on some of the important aero details. Hucho made the point, in fact an entire chapter, on how attention to details could add up. If I had a family of five and needed a soft riding long trip car, I'd consider it.

[aerohead]

Originally Posted by MetroMPG

Should I be rewarding slow, incremental improvements by regurgitating corporate press release tidbits about cars that "almost" get to .28 Cd?

I feel kind of dirty.

Darin,it's all a move towards greater knowledge.I appreciate the ears to the rails big-time! Thanks!

[MetroMPG]

Good point. When EcoModder was new, I recall seeing more than a couple of threads on traditional "enthusiast" forums along the lines of how crazy we (EcoModders) were to be partially -- or mostly -- blocking our grilles, for example.

With companies like GM, Ford, BMW and others now doing this as original equipment on some production cars, that blather has subsided.

Educating the masses.

[MetroMPG]

Originally Posted by cfg83

MetroMPG -

One mm at a time? I'll stick with one M&M at a time.

I'd go for Hershey Kisses, but whatever floats your boat (in the most hydrodynamically efficient manner)!

[Peter7307]

Can't help thinking the wheelarch "ears" are NOT helping !

Sorry to be cynical here but .28 is not all that good.

Citroen managed .29 in 1974...also on a 4 door , 5 seater production sedan ;the CX model.
The original version had .30 but later variants had .28 / .29 depending on equipment and specs etc.

Panel fit was somewhat umm... variable (yes we'll call it that to be kind) and there were gaps you could put your fingers through (between the headlight and the bumper for example) so some "tweaking" should be able to drop the numbers even further.

Peter.