Using the fan, heater

[BailOut]

Yes, using the heater and fan does use more fuel. The hit is not nearly as large as with a/c but it is there.

The fan requires electricity and the alternator puts more of a load on the engine to produce it. The engine also produces only so much waste heat that makes it into the cooling system, and it often experiences drops in the coolant temperature which causes the ECU to cause the engine to burn more fuel (by running richer and/or at a higher RPM). This means that sometimes you're pulling heat from the system that the engine cannot afford to lose, but other times it is happy to dump excess heat.

Sometimes you simply need to use the heat. One should never allow themselves to get too cold in the car. However, like any other use of energy it is best kept to a minimum. Wear a coat and hat and gloves and you'll find you don't need to use the heat nearly as often.

[Yar Is Word]

http://www.yarisworld.com/forums/sea...earchid=433412

[otterhere]

Originally Posted by Yar Is Word

http://www.yarisworld.com/forums/sea...earchid=433412

Something's very wrong with the design if you have to ADD parts to make things work properly. Sloppy and disappointing coming from Toyota, IMO.



Now back to being positive!

[blktiger60]

Originally Posted by otterhere

Something's very wrong with the design if you have to ADD parts to make things work properly. Sloppy and disappointing coming from Toyota, IMO.



Now back to being positive!

The Yaris isn't the only vehicle out there that does this.
The Dodge Calibre does it too, that's one I know of for sure.

[colb]

Originally Posted by BailOut

Yes, using the heater and fan does use more fuel. The hit is not nearly as large as with a/c but it is there.

The fan requires electricity and the alternator puts more of a load on the engine to produce it. The engine also produces only so much waste heat that makes it into the cooling system, and it often experiences drops in the coolant temperature which causes the ECU to cause the engine to burn more fuel (by running richer and/or at a higher RPM). This means that sometimes you're pulling heat from the system that the engine cannot afford to lose, but other times it is happy to dump excess heat.

Sometimes you simply need to use the heat. One should never allow themselves to get too cold in the car. However, like any other use of energy it is best kept to a minimum. Wear a coat and hat and gloves and you'll find you don't need to use the heat nearly as often.

I think I recall that cold enrichment does not occur above 135F or so on most cars... it's safe to say that your heater will never pump enough heat to get the car into the cold enrichment temperature zone under normal operating conditions. (Actually, I have had this problem in my '85 MR2 when temperatures were below 15F while driving at highway speeds, but that involves problems the Yaris does not have.) The motor produces at least as much waste heat as it does useful work, and even for a tiny Yaris it takes a LOT of energy to push around a 2500+lb metal room on wheels. Using the A/C is using energy you would not otherwise have wasted. Using the heater is using energy that you were throwing out the radiator already, and if the motor is being cooled into its cold-enrichment zone then your radiator has become extraneous.

The fan takes up close to zero power, especially at the low settings. It's insignificant compared to the headlights, much less the A/C.