Testing an aerodynamic boat tail - 15% better MPG - Geo Metro

For more info see: http://ecomodder.com/forum/showthread.php/project-removable-geo-metro-boat-ta...

15% better fuel economy at 90 km/h (56 mph).

On-road yarn tuft testing and fuel economy testing of an aerodynamic "boat tail" mockup on the back of a 1998 Geo Metro (Pontiac Firefly) hatchback. The tapered form dramatically reduces drag and improves efficiency by minimizing the size of the car's wake.

Category:

Autos & Vehicles

Tags:

• aerodynamics
• tuft
• testing
• Geo
• Metro
• Pontiac
• Firefly

[rickylarch]

Nice work, and lot's of it. Inspirational. Can't wait to see the final version.

O4b

[ThomasD1962]

Lower the a car about 1,5 inch and raise the tail a bit and hey presto! Another 10%!

[josephdupont]

Proud of you.. but is it legal?

does the exhaust come out of the back or underneath.

You could use that extra space for sleeping quarters to live in your car.

[josephdupont]

Proud of you.. but is it legal?

does the exhaust come out of the back or underneigth.

[josephdupont]

is it really legal??

[evlogix]

As AndY1ksi stated, the efficiency gain is actually greater at higher speeds if you consider the energy outputted. The motor, however, *might* be less efficient at 70 mph as opposed to 56 mph, but that will ultimately depend on your gearing.

[sonicballer8888]

@Yeltuh888

the reason fuel prices went up is because you guys are still buying them with your expensive bad for the environment cars. so blame yourselves.

[DanFrederiksen]

very interesting experiment.

I think the tail has to be flat to the ground side though since you can't suck in air from the ground. will only create a vacuum with turbulence.

plastic sheet cover under the car might also improve the drag.

what we really need though to really explore aerodynamics is a good freely available virtual vindtunnel software. they either suck or cost a trillion or only works under some obscure linux bullshit.

a windows application running on GPU. now!

[DanFrederiksen]

@Yeltuh888 no fuel prices should go up and up. gas car has to go

[Yeltuh888]

generally speaking

or to myself..

[mr82769]

Erhm... Who are you talking to when you say "bring down the fuel prices" ?

[AndY1ksi]

Excellent testing!

The fuel consumption difference would be even higher, at higher speeds.

The power to move (throttle) an object through the fluid (air) increases by the power of 3 in regards to speed.

The energy (consumption) required to move the object from A to B increases by the power of 2 in regards to speed.