How many miles per gallon are saved by not using the air conditioner?

Answer 1

Around 2 to 4 mpg are saved, depending on the engine size, when the ac compressor is not turned on but that is if your sitting still in your car while it idles.

When you are driving with your ac turned off but have the windows down for outside air, the aerodynamics (how well your vehicle slices through the air) of the vehicle is altered because air is coming into your windows and the back window of your vehicle acts as a parachute so your engine still has to work hard to overcome the wind drag.

Ultimately, I suggest that you use your ac while driving because the compressor and wind drag both affect the mpg about the same amount, but at least you will be cool.

If your compressor is worn out but working, it puts more work on the engine but again, being comfortably cool is the better option.

For the best mileage:

*Keep tires inflated properly

*Change your air filter when your manual recommends to (more often if you drive on a dusty road a lot

*Change your thermostat when your manual recommends to

*Change your oil and filter " " " " "

*Change your spark plugs " " " " "

*** KEEP YOUR MAINTENANCE UP TO DATE

*From a stop, reach the speed limit in around 8-10 seconds because increasing speed uses more fuel than maintaining your speed (don't punch it. Every vehicle is different.)

*Drive at a consistent speed (stay within 2-3 mph of the speed limit)

*Coast down hills

*When coming to a hill, slowly accelerate before reaching the hill and let off when you reach the top of the hill.

*Only fill your fuel to half or 3/4's of a tank. Less weight equals better mileage.

*Make sure your fan/ serpentine belt is tightened to the vehicle specs. If it's too tight your engine has to work harder.

Hope this helps