CASE-STUDY: Mercedes-Benz C-111 / III (Cd 0.178)

[MetroMPG]

Originally Posted by The Atomic Ass

14.7mpg @ 195mph?!

Reminded me of the Bugatti Veyron top speed fuel economy stat...

3 miles per US gallon (1.3 km/l/3.6 mpg-imp) 1.39 gallons per minute @ 408.47 km/h (253.81 mph)

Bugatti Veyron - Wikipedia, the free encyclopedia

[aerohead]

Originally Posted by Christ

Dorsal ridge - Stability at speed?

Yes,the fin keeps the center-of-pressure behind the center-of-gravity.

[aerohead]

Darin,thanks much for the formatting!

[aerohead]

tasdrouille,thanks for the pic!

[MetroMPG]

So the fin is for crosswind stability?

Thank TestDrive for the formatting - I just pasted his work into your post.

[aerohead]

Originally Posted by MetroMPG

So the fin is for crosswind stability?

Thank TestDrive for the formatting - I just pasted his work into your post.

I think so.Morelli licked the stability issue,but it came a little later,and the sharp-edged front fenders on the M-B lend themselves to cross-wind issues.Morrelli rounded everything dramatically to let pressures bleed away.The tapering tail doesn't have much of a "moment" in gusts,and the vertical stabilizer adds some area aft,to help maintain the CP behind the CG,to provide for "oversteer",which is preferred at high speed.If the car should "weather-vane",it will turn itself into the wind,canceling the yawing moment.Should the car have more area in the front,if it yaws away from the gust it will "catch" more air,turning a larger "face" at the gust,and the yawing moment can increase to a level such that the driver's steering inputs cannot compensate.Don Schroeder,the fella that tested my CRX at Chrysler was killed in the wreck of a RennSport V-12 Mercedes at Ft.Stockton(where A.J.Foyt fought hellacious crosswinds in the OLDS Aerotech).The investigation was unresolved last time I looked. It looks like the engine blew,and if he was in a controlled power-slide at the time,he would not have had power to control the rearend.If the winds were strong that day,as they often are,he may have had too much to compensate for without the power.------- These speeds are obviously potentially lethal,and I suspect Mercedes wanted to stack the deck,best they could in the event of bad air with the C-111.

[instarx]

Originally Posted by tasdrouille

I love that car

Me too. I'm old enough to remember being blown away by the C-111. The picture above is mostly aero add-ons to the normal C-111 body. Someone at M-B clearly had a nice aero research budget that year.

Here it is in its normal clothes and in racing trim. Note the front wheel skirts.

[NeilBlanchard]

Nice hats!

[hypermiler01]

Also remarkable for being a performance supercar powered by a diesel engine, for the purpose of improved fuel economy.

[basslover911]

Hmmm 195mph and 14mpg... now that is BAD-A!

Think people stare at basjoos civic? Imagine this!

People would think its an airplane about to take off or landing from the rear fin!