How much gas does using AC in your car eat up?

Question

Im trying to save my gas. Does using the ac eat up gas? If so how much, and what else can i do to my car besides inflating my tires to save better gas?

Answer 1

None

Answer 2

True, the drag from opening windows makes you lose as much as running the AC on most models. On many new cars the AC only take 1 to 2 MPG. Don't use it if your trip is so short the car never really cools off anyway. Keep tires properly inflated. Remove all the "stuff" from your car - extra weight takes more gas. Take your foot off the gas when you see red taillights ahead and coast instead of rushing up close and hitting the brakes. Try not to come to a full stop - unless at a stop sign - since it takes more gas to get back up to speed while in low gear. Carpool. Park right at the entrance to the shopping area or store instead of driving around looking for the closest parking space; the walk will be good for you, too. Keep close to the speed limit; consumption goes up when you go over 70.

Answer 3

If you're driving on a freeway, you're better off leaving the AC on. Driving at high speeds with the windows open creates much more drag on the vehicle, and may end up using more fuel in the long run. Either way, the difference will be very minimal, so why not be comfortable?

As for city driving, yes. You'd save some gas by not having the AC running. Personally, I feel there's nothing worse than sitting in a stifling car in a traffic jam. I'll gladly pay the few extra cents and and be comfortably cool.

Answer 4

AC does use some gas but not very much. You might not even notice it. I would doubt it would be even as much as 1 mpg.

Also if you're going faster than about 50 mph, using AC is cheaper than opening the windows. The drag caused by open windows is more than the AC uses.

To save gas, besides inflating your tires, if you stay under 55 mph you will save a lot of gas. As you go faster and faster, you get worse and worse mileage. Try it and see!

Also you could use your car less. If it's only a few blocks, walk! Or plan trips to do several things at once.

I ride my motorcycle almost everywhere. It is my primary form of transportation. I only use the car when I need to carry something big, or when it's raining, or when I need to carry more than one person. The bike gets about twice the mileage, so I save a lot of gas (but besides gas the bike is a little more expensive to run).

Answer 5

I have studied this in detail since I got a car with on board computer so I can see consumption instantaneously and per tank and per journey. There is no fixed penalty for air con because it depends on the size of engine, the weight of car and the relative power consumption of the air con. It very clearly does consume extra fuel and with my 1.7 turbo diesel I can see a 5 to 10 % penalty. As already said, this is better than driving with windows or sunroof open as the turbulence of open windows creates more drag. To suggest that an electric system is more efficient is nonsense as you then get addedd inefficiencies through the electric motor drive. I would not say the air con eats up gas but it does consume a but more. If you have one of the modern cars which cuts fuel when your decelerating then the air con actually comes for free at those times. If you are facing a long steep hill then you can just about notice a drop in power with air con especially if your car is underpowered to begin with. If your trying to save on fuel, then you should start from basics, optimise your use of the car, choose a fuel efficient car for the type of driving you do, dont carry round extra weight, dont keep an empty roof rack on top as the turbulence of that uses fuel, adapt your driving style to avoid braking through advance planning,.

Answer 6

I own a Rover 25 with a 1.4ltr engine. When I first bought the car I noticed a lack of engine power when the A/C was on and queried the car retailer about it.
I was informed by their mechanic that running the A/C "steals" approx 15-20% of the engines power as the engine is also being used to drive the A/C compressor.
Based on that premise you would need to drive the car 15-20% harder to get the same performance from it, thus using 15-20% more fuel...
Needles to say this is all estimated, but you get the idea!

Incidentally if the compressor on your A/C system is electrically powered rather than belt driven (as is the case in rear or mid engined cars) then the extra load falls on the alternator, which supplies the power for the compressor, and your fuel comsumption will be affected slighty less.

Answer 7

Dont be so paranoic. If it is warm and stuffy I put the AC on to feel more comfortable the cost of the gas(petrol) is not a factor. It obviously uses more petrol to use the AC but I don't worry about it . Are you doing all this to try to save money or from a green point of view?

Answer 8

Running the A/C takes several mpg off your achieved gas mileage. Keeping tires properly inflated is good for about an mpg as I recall. Not running tires under-inflated will make the tires last longer however.

Answer 9

It makes use of much less gas to stress with the AC on then it does to stress with the domicile windows open becuase of the resistance. The ac can pull a sprint from the mpg yet ordinary you dont lose even a mile consistent with gallon.

Answer 10

I have run four different cars, one month with ac on all the time, one month with it off. I couldn't find any difference. It must use fuel, but, for me, it was very little.
Drive with a light foot - gentle acceleration, use the engine for braking, not last minute braking.
Keep in a high gear longer.

Answer 11

AC eats up gas far quicker than you'd expect (varies car by car), so turn it off if you don't really need it. Away from other traffic open your window.