Does it save fuel by keeping car ac at a lower cooling?

not that you are going to notice. is 50 cents a day to much to be comfortable?

yes it does. Law of Conservation of Energy means that is the AC system is doing work it is using energy to do that work. The harder its working the more energy it needs to run and it gets that energy from the engine, so more fuel must be burned.

How much depends on the size of the cooling system and how hard your running it.

The mythbusters argument to this needs careful consideration, as is often the case they come to conclusions that are gross generalisations. They compare AC energy use with the disturbance of the air flow over the vehicle that occurrs when windows are wound down. This is science for peopel who like newspaper headlines and is far from the truth.

Often a window need not be wound down or only a little. Also some vehicles are so aerodynamically poor that the change in drag would not be significant. You would have to test all vehicles in all situations to make the conclusions meaningfull.

Thats why scientific papers take years to produce rather than a 10 minute program slot.

Ultimately unless you are sure of the drag increase on your particular car, and drive with windows right down if the ac is off you cant make that comparison.

If you are in a climate that is not extremely hot and can just crack the windows open the cold air machine will cost you more. If you are in the desert, you still need to know the aerodynamics of your car, (is it a shoe box!). and dont forget, if your driving in slow traffic or stuck in a jam opening the windows full wont have any effect what so ever on your fuel consumption but the AC certainly will.

Using the air conditioning costs fuel. Period. There are a lot of jokers on here who think cold air is free. It isn’t. The more you use the air conditioner, the more fuel you consume. So if you keep it as low as possible, you will consume less fuel. However, and this is a big however, there are major difference in cars. Bigger motors will experience less difference in fuel mileage between running the air conditioning a lot or a little. Smaller motors will feel much more power loss if the air conditioning is running. They will really see a dip in fuel mileage the more the air conditioning is used. Air conditioner compressors are the biggest draw on engine power. Secondarily is the increased electrical load. Air conditioning compressors are either on or off, there is no in-between. The higher the setting on your system, the more time the compressor stays on, and the more fuel you burn.

till the compressor is running it does not matter what temperature you have set. If the set temp is high and the AC never trips then more fuel is being consumed. And if the temp is low and the AC trips at regular intervals the consumption is less.

not enough to notice its cheaper in fuel to have the ac on than it is to turn it off and open a window because of the wind drag

NO IT COST LESS TO PUT IT ON MAX DUE TO THE AIR OUT SIDE IS BEING USED IN ANY OTHER SETTING THE CAR WILL COOL BETTER IN THE MAX AND NOT PULL ANY HARDER AS YOU ARE USING THE AIR INSIDE THE CAR OVER AND OVER SO COST LESS TO DO THAT WAY THEN COOL THE OUT SIDE AIR IF YOU WANT TO SEE THE BREAK DOWN ON AC VS WINDOWS DOWN GO TO MYTH BUSTERS ON THE NET THEY DID A COMPLETE STUDY ON THIS AND ITS CHEAPER TO USE THE AC WITH WINDOWS UP THAN THE WINDOWS DOWN AND MESSING UP THE WIND DRAG ON THE CAR BEST OF STUD Y’S IVE SEEN IN 10 YEARS, OLDER COMPRESSORSRS USED MORE POWER FROM ENG THAN NEWER ONES SO YOU WILL GET ANS BOTH WAYS DUE TO NOT STATING THE YEAR OF CAR BEST OF LUCK JFB

Nope, not according to mythbusters. It makes a difference which makes no difference.

Running an AC on low or normal is making it cool hot air from outside the vehicle.

Running an AC on High, Max or Recirc is cooling cooled air again. Unlike water, hot air does not cool faster than cool air.

Hot water freezes faster than cold water. True fact.