When a car's heating system is turned on, is it likely to consume more fuel ?

Question

An air conditioner's compressor causes the engine to run at higher rpm. But the same may not be true in heating. In fact, I think it is merely the engine's exhaust heat that is diverted to heat the air inside the cabin. Is that true?

Answer 1

This is true. Excess heat in the cooling system is simply diverted into a small radiator (called the heater core) the cabin, and air is blown through it. It only uses more fuel if you're trying to heat the car before it reaches full operating temp - in which case, it's trying to heat the engine and the cabin. This means that the engine will take a little longer to warm up, and will be running rich for that extra time. Always try to warm the engine up before turning your heat on (not the blower, I mean the actual heat control - this is what diverts coolant into the cabin.)

Answer 2

No A heating system runs off your Radiator . The same water and Anti-freeze that cools your engine , runs through a heater core and a fan blows the warm air out. It may help fuel consumption! A/C dont make engines run at a higher rpm they draw horsepower from the engine and make the motor work harder to turn the compressor, but the compressor also runs when you have the heater on Defrost . But not on just regular heat!

Answer 3

While the AC is turned on, the compressor is working to run the AC system, so that is why it will use more gas, however, the heater, if it has any effect at all, should maybe minorly improve fuel economy, not likely, but IF it has an effect, i think that would be it. It uses the engines heat to heat the vehicle, bu using the heater, you thus lessen the strain of heat on the engine. I know crazy and stupid, but closest i can come to explaining my logic. But more than likely, it will have no effect at all

Answer 4

see there are many ways a car is heated. like in early days directly gasoline was also heated (1959), then there are 12 v electric heaters which also leads to more fuel consumption. now a days many cars specially diesel ones having turbochargers uses exhaust gas heat to warm up the inside of a car.cars also have heating system where heat is taken from the radiator . the heat comes from the hot coolant while it is passing through. but to get that heat you have to use fans which is any way gonna lead to more fuel consumption.so even if the heating system is using exhaust gas the fan used to pump in the heat is going to increase your fuel consumption.but less

Answer 5

The heater uses the hot coolant in the engine to heat the air thru a heater core. Kind of like a mini radiator inside the passenger compartment with a fan to force the air thru it.

Answer 6

yes it will use more fuel cause it takes the hot water from the engine coolant so if you take it away it has to be replaced by the engine to get back to the original temp before you turned on the heater hence more fuel, but in saying this it is very minimal. also in very cold weather you use more fuel to keep the engine and the heater at the correct temp as to in warm weather you use less.
hope this will help with your question Brian.

Answer 7

No - it uses waste heat from the engine by way of the coolant - not exhaust heat - the heat would only go to the rad to be shed anyway.

The hot water is "free" as it is produced as a by-product of keeping the engine cool. All engines produce heat during their combustion cycle - water cooled engines shed this heat to the coolant.

Answer 8

No its using the hot water that is always produved by the engine anyway. If you diverted the exhaust into the car you would be dead.

Answer 9

Just the tiny bit the alternator takes to run the heater fan. The heat is free. Maybe one gallon in five years.

Answer 10

no its the same compressor that either gives out cold air or hot air i.e only the temperature changes. so using the heater is like using the a/c so it will consume more fuel....