Running the a/c or having your window down when cruising at ~75 mph?
2006-09-19 09:18:50 · 11 answers · asked by PostGrungeJunky 3 in Cars & Transportation ➔ Commuting
Modern automobiles are engineered to exacting standards. One of the most important design elements of modern cars is the aerodynamics of the car which are determined by the shape and size of the car. Modern vehicles are designed in wind tunnels to maximise air flow around a vehicle, with the windows up, to increase fuel economy. Due to the properties of air flow, opening your window creates an opening for air. Since the air moving around you car is of a higher pressure(since it is moving) it is pulled into your car by the area of low pressure air inside (not moving) this creates drag, and drag kills fuel economy, more than the drag placed on your engine by the A/C unit. So, in short, windows up and air conditioning on for max fuel economy. Hope this helps.
2006-09-19 09:34:39 · answer #1 · answered by shifty67 3 · 0⤊ 1⤋
Shifty67 provided the best answer so far (give him the 10 pts), but I wanted to add a couple of things:
Each car behaves differently aerodynamically, due to their different shapes. Some cars will be more impacted by having the windows down than others.
Also, drag is a function of the square of the cars speed, so wind resistance goes up dramatically at highway speeds. The general consensus is that above 45 mph, drag hurts economy more than A/C does.
2006-09-19 10:05:52 · answer #2 · answered by Harry 5 · 0⤊ 0⤋
One Mythbusters episode they drove identical vehicles with the same amount of gas around a race track at 45 mph. The vehicle with the ac on ran out of gas first, approx. 20 miles earlier.
2006-09-19 09:27:57 · answer #3 · answered by Anonymous · 0⤊ 0⤋
If your cruising at 75 mph why worry about gas mileage... be cool man...
2006-09-19 09:22:09 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Mythbusters did this, I think the car with the windows down ran out of gas earlier then the car running the A/C. Check their website
2006-09-19 09:27:29 · answer #5 · answered by debean75 4 · 0⤊ 1⤋
if you're driving on the city, then the domicile windows down, yet when you're driving street speeds, having the domicile windows down extremely motives wind drag, and also you've gotten worse gasoline mileage than operating the air
2016-11-28 02:25:03 · answer #6 · answered by cassone 3 · 0⤊ 0⤋
Having the window down...but if you are going some distance, you may just as well blow the AC.
2006-09-19 09:26:48 · answer #7 · answered by amazinbabyfaceona5footframe 2 · 1⤊ 0⤋
it doenst affect ur mileage. Mileage is just distance.
Gas wise if u put your window down u use less gass
2006-09-19 09:27:28 · answer #8 · answered by `·.¸×°×Comadrejaװ׸.·´ 3 · 0⤊ 1⤋
window down
2006-09-19 09:20:35 · answer #9 · answered by Al Bundy 4 · 1⤊ 0⤋
a/c when on the highway, windows down while in the city.
2006-09-19 09:21:39 · answer #10 · answered by JimL 6 · 0⤊ 0⤋