CraZydudE

I forgot where I heard this from. But it's said that when you have heat on in your car, it doesn't burn up gasoline to form source of the heat, instead, the heat source comes from the engine Can anybody confirm this?

JTso

iTrader: (2)

Well, it does use fuel to produce the heat... It requires fuel to run the engine, which in turn heats up the coolant. The warm/hot coolant then circulates through out the entire cooling system, including the heater core. The heat comes from the blower fan blowing air through the heater core.

TSXsurf

That's a confusing question - the heat that you feel coming through your venuts is coming from the heat put off from the engine. That heat is being formed within the engine by the gasoline burning (the combustion within the engine). So on a cold day, you have to let your engine run (gasoline combust) for long enough to warm up your engine before you can get hot air to come through your vents. Hope that makes sense.

CraZydudE

I don't think I word it right....I meant to say, will the car burn up more gasoline well the heat is on? Or will it use the same amount?

Arcticcl9

I think it makes more sense to say "Heat uses no more fuel than A/C" since you're not driving a compressor (if A/C is disabled during heating). The only fuel used is the fan used to circulate the heat into the cabin...heat comes as a byproduct of the internal combustion engine.

MoFocker

jesus christmas people, stop looking so far into the question and just answer him!!

NO it does not use MORE fuel when you run your heat.

JTso

iTrader: (2)

Haha... since it's a technical question, thus requires a technical answer.

Since heat comes from air blowing through the heater core with coolant flowing through it, the heater core is basically a secondary radiator. If the heater valve is opened before the coolant temp has reached to the operating temperature, the coolant has to flow through the heater core and therefore, increasing the warm up time. Which means, the coolant temp sensor continues to signal the ECU to add fuel in warm up mode until the operating temperature is reached. At that time, the thermostat opens and coolant circulates the cooling system.

So the answer is...

Yes, it does use more fuel when the engine is cold with the heat on.

No, it doesn't use more fuel when the coolant has reached operating temp and stabilized.

Xtremespeed2102

here let me complicate this.... you shouldnt be warming your car up in park or N. you should be driving it like its still under that 600 mile mark, babying revs and what not. its the best way to warm up the car cuz the gas is being used for something instead of a high idle rev. also, you are warming up your transmission and other fluids by gently letting the car warm up its moving parts.
and yes the heat wont come on full blast until the engine has some heat going on. so drive that car until it warms up 10 min or until the needle is up i ususaly can feel when shes warmed up any way

Jim Holloman

The answer to your question, in general, is no.

However, there are two exceptions. With climate control, the operator is not turning on the heat nor the A/C. They are setting a temperature. On borderline days (but certainly not in the dead of winter), the operator may believe that they have turned on the heat -- but have actually turned on the A/C The other exception is when the climate control is put into defrost mode. In defrost, both heat and A/C are turned on to reduce the humidity of the air inside the car. Anytime the A/C compressor is running, you are using a little extra gas.

What I like to do around town on cool, but not cold, days is to turn the Climate Control on, set the temperature to HI, and then adjust the temperature by raising and lowering the driver's window. As long as your are moving, the vents will emit a good bit of warm air without using the fan motor.

biker

Simple lay person answer: Having the heat on or off makes no discernable difference to gas milage of vehicle.

CraZydudE

oh okay. Now I can have the heat blazing without worring about using more gas!! Thanks for the answers people

sauceman

Yes. It's no like you're using a "wabasto" like they do on trucks when they're parked.