Does the ac or the heater waste gas in a car?

Answer 1

yup....

Answer 2

The heater uses some gas as does anything you use (lights, horn, radio, a/c whatever.) The a/c will use a lot of gas, normally about an extra 5% - 10% depending on how high you have it and your vehicle.

As for the heater it uses less as it only uses a little extra electricity to run the fan on it. The heat comes off the motor anyways, just into the passenger compartment instead of through the radiator.

So use your heat as much as you want or need to, it isn't costing you much per year. But use the a/c as little as possible as it will cost a lot over the course of a summer.

Answer 3

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AC does, heater does not

AC works by compressing then expanding gas, usually some sort of freon, in a closed circuit. The gas is compressed by a mechanical compressor driven by a belt off the engine crankshaft. It takes power from the engine to turn this compressor. It takes extra fuel to generate this power.

NOTE: On many newer cars, when the outside air is over 45F, the air conditioner compressor runs to de-fog the windows. Below 45, it only uses air or heat.

The heater works by passing air through a heat exchanger with hot engine coolant circulating through it. The heater only uses a small amount of electrical energy to run the blower fan. This isn't enough energy to make a difference on fuel mileage.

^- What he said.

Electrical components are drawing off the battery, not the engine, so there is no effect on gas mileage for electrical components - windows, fans, radio, etc do not effect mileage. The alternator and regulator are the only components that effect mpg as they are belt driven and their job is to keep the battery charged no matter what electronics you run.

Basically, if it runs off a belt in the engine bay, it effects mpg and horsepower. The A/C compressor does, so it will effect mpg, but I wouldn't call it wasting gas.

Also, at highway speeds, it is better to use the A/C with the windows up than to not use it and have the windows down as that increases drag and will lower mpg.

Answer 4

The a/c will waste more gas while it's on than the heater because it is belt driven and requires quite a lot of energy to perform.

Contrary to previous answers, the heater WILL waste gas in the sense that while it's on, it has an electrical draw (some cars more than others) and thus will drag on the engine via alternator.

Answer 5

AC does, heater does not

AC works by compressing then expanding gas, usually some sort of freon, in a closed circuit. The gas is compressed by a mechanical compressor driven by a belt off the engine crankshaft. It takes power from the engine to turn this compressor. It takes extra fuel to generate this power.

NOTE: On many newer cars, when the outside air is over 45F, the air conditioner compressor runs to de-fog the windows. Below 45, it only uses air or heat.

The heater works by passing air through a heat exchanger with hot engine coolant circulating through it. The heater only uses a small amount of electrical energy to run the blower fan. This isn't enough energy to make a difference on fuel mileage.

Answer 6

The only way it can waste gas is if the AC compressor is running while the heater is on. If you have the Defrost selected then the AC compressor is on to reduce humidity and condensation on the windshield.

Answer 7

In older cars there was noticable difference in the gas mileage, but I think the AC pumps have become more efficient in newer vehicles so the difference is hardly noticable. Heaters dont do anything though.

Answer 8

Yes, the a/c does. The heater will when selector is in the defrost position in most cars.

Answer 9

A/C-----yes
Interior Heater----No

Answer 10

not much but who cares? why spend 1200 dollars for AC and not use it because u get 30 mpg instead of 32..

Answer 11

cars use more gas with either one of them running than they do without them on.