Does turning your car on with the air conditioning on effect the gas?

Question

If the last person to drive the car left the air conditioning on when they turned the car off, does it use more gas to turn the car on with it still on? My grandmother has been on my case about this and I want to know if there is any merit to her concern.

Answer 1

I think all vehicles built within the last 15 or so years have an automatic cutoff device for the AC. When you start the car, or when you floor it and it drops down into passing gear, the AC is temporarily disabled so as not to drain power from the battery or the engine as the case may be.

Answer 2

Yes, the AC can eat up 5 - 15 HP, which is a considerable load on a small engine.....It will definitely affect the mileage, but not as much as driving with the windows open.... the drag from air resistance causes greater lossese than the AC.

You don't have to worry about starting the car with the Air on. Most modern cars will lock out the compressor while the starter is turning. But once you're going, the energy for cooling is coming out of your gas tank.

Answer 3

Of course it will burn more gas with the AC left on,since almost everyone is likely to start the car up then go,without checking anything else,unless the temperature inside the car is unbearable,then we start to look for the temperature control.

Answer 4

not the gas but it is something added that the starter has to turn that cuts down on its life

Answer 5

Technically, YES, but not enough to matter.

Just humor your grandmother. She's old and you won't be able to change her mind, so why try.You need to learn to "pick your battles", and this is one you won't win.

Answer 6

when the a/c pulley clutch is disengaged it wont waste gas, when you first fire it up, it will be engaged. so yes, it wastes.

the question is, do you care that you waste 1 teaspoon a week?