Comments from other sites about basjoos' Aerocivic

[MetroMPG]

Also: "different is bad."

[brucepick]

They'll all remember that car when gas hits $6/gallon.

[DifferentPointofView]

If you've seen "I am Legend" you'll see the gas prices. 6.30 something? Wouldn't the aerocivic create lift though at high speeds? that can be bad if your on the German Autobahn.

[newtonsfirstlaw]

Originally Posted by DifferentPointofView

If you've seen "I am Legend" you'll see the gas prices. 6.30 something? Wouldn't the aerocivic create lift though at high speeds? that can be bad if your on the German Autobahn.

I suspect it would create more downforce at the back, because there's going to be suction going on underneath the back, more so than at the top of the vehicle, because air can only come from the sides. I'd be surprised if lift was an issue.

[MetroMPG]

Basjoos has answered this one before, and if I remember, his impression was the car felt just as stable at 90 as at lower speeds.

[basjoos]

I've had it up to 100mph with no stability issues.

[newtonsfirstlaw]

Originally Posted by SVOboy

Sadly, most of the "performance types" don't understand aerodynamics and tend to think that weight is more important.

Most "performance types" are fixated on 0-60mph, 1/4 mile times, and the maximum speed at which you can still get wheel spin. Hence the focus on weight, power and low end gearing, to the exclusion of everything else.

[basjoos]

[*] imho 40-50 mpg is a decent amount, why drive a piece of poo to get a little more

What he mean "a little more", I'd would need to cruise at over 90mph to get my mpg's down into the 40-50mpg range. On those few times when (mileage be damned) I do cut loose and cruise in the fast lane with the speeders, its amazing how effortlessly it cuts through the air. But normally I avoid speedng since my car is enough of a cop curiousity magnet without giving them an obvious reasong (speeding) to pull me over.

[newtonsfirstlaw]

Originally Posted by basjoos

But normally I avoid speeding since my car is enough of a cop curiosity magnet without giving them an obvious reason (speeding) to pull me over.

And I don't imagine they'd have much patience waiting for you to coast down to a stop. "But officer, think of the kinetic energy you've made me waste!"

[DifferentPointofView]

well, I was just thinking of the lift problem because the whole car is shaped like an airplane wing, and since there is more down force towards the rear of the vehicle, this would lessen the weight on the front end, that could result in the front catching a wind gust and lifting the front end off of the ground. As I recall the Ferrari F430 has no lift at all, but creates around 360ish lbs of downforce at 100mph, even more weight at 180. But the downside is it's drag coefficient is like .32, which isn't real bad at all.

Most every car creates lift because of it's similar shape to an airplane wing, uneven raised surface on top, flat surface on bottom. The air going over the top has to go a lot faster than over the bottom so that the air meets up at the back at the same time as the bottom. This creates a high speed, low pressure on top and a low speed, high pressure on bottom, creating lift.

Now this only becomes a factor when you go at speeds up past 100mph, depending on the vehicle. A boxy high off the ground oddly shaped vehicle at 100 will have more lift than a low to the ground low slope windshield vehicle with front lip spoilers and rear inverted wings. Most lift is only felt at speeds of 150ish and up. Which is why most normal vehicles traveling on the autobahn at 120ish can without problem.

A vehicle that is symmetrical in every aspect will have an equal distribution of down force and lift, resulting in an equilibrium that makes no lift, and no down force. Sports cars try and speed the air on the bottom of the vehicle and slow the top by using flat bottomed vehicles to try and reduce drag and add things to make the incoming air speed up, and as it goes out the rear to speed up, they also add spoilers and pieces that cause drag over the top of the vehicle, resulting in the opposite of an airplane wing, even though it was originally in the shape of one.