Why do people think that it saves gas to not use your a/c?

Question

i have seen several blogs across the web and a few people on here asking about it and people actually believe that it is better for MPG to have the windows down instead of running the a/c.... that is ridiculas.... think about.... first off when a manufactorer calculates the MPG that car will make before you buy, it is done with the windows up. second reason is regardless if the a/c is on or not the belt still has to go around the pulley of the compressor so the engine strain is still there. and last but not least, when the windows are down the drag created will cause poor gas mileage and that has been proven.... so, if you object with me, please tell me......

Answer 1

I Agree  with john paul on this one,he is actually correct in

what he says.

Answer 2

that myth was in reference to the older cars, back when they used r12 in the a/c's the com pressers then were not advanced and computerized like they are today. on a newer car your not going to see and loss in power or gas mileage the compressors and so low voltage and they technology of Bering's and belts they hardly put a draw on the car.

Answer 3

Here is the real story at speed 65 mph or so wind turblence may make the car use more fuel. The belt is not turning the compressor it has a magnetic clutch. The compressor which is a pump that can draw approx 4 hp at 4,000 rpm compressor speed.  A/C on can draw down gas milage as much as 2 miles a gallon. Synethic oils can give back 3/4 to 1 mile a gallon clean air filter can make 1 mile a gallon. Keeping good quality tires properly inflated and smooth body work and wax job? Empty out extra weight that saves milage too. Answers really likes year make and model of car and how many miles?

Answer 4

I also agree with John Paul. I don't know engines nearly as well, my experience was simply working for an ambulance company with a couple of old beater rigs. If we were running to an emergency call in the summer on the interstate, we'd turn off the A/C and the engine would be able to go about 3 mph faster. Evidently, the A/C just used that much power.

Answer 5

it does