But what about the color? Originally Posted by oilfieldscumAs has been previously stated, Red Ones Go Faster.
An addendum to this is "da red wunz go fasta!"
It's just plain science.
In the same way, the generalized Ork belief that vehicles or aircraft painted or otherwise colored red have higher top speeds than those painted or colored otherwise ('da red wunz go fasta!') actually results in measurably higher top speeds for Ork vehicles painted red. Originally Posted by http://en.wikipedia.org/wiki/Ork_(Warhammer_40,000)#Weapons
Actually spoilers increase drag as do fins. Originally Posted by oilfieldscumWhen travelling through fluids or gases, the speed of the substance you're passing through affects how much pressure it exerts on your vehicle (ie, the Bernoulli Effect, as WU pointed out). Because of the steep angle of a lot of sports cars, you can get a split airflow coming off the back rear roof to the trunk area, which causes instability & drag because of the low pressure area you've just created on the back of your car. Rear spoilers & wings try to relieve this by essentially creating a longer, smoother line for the air as it flows past your car.