Heater - When you turn it on does the revs increase??

[trace1967]

Happens with mine and I dont like it as I keep thinking its using too much fuel. It goes up then drops down but not back to the original revs when its idling without the heater on.
Is this normal??

[hornetrider]

Your aircon button on?

[MX-5 Lazza]

The revs will rise if you put the fan on to position 2 or above. That's normal and is to allow the idle to cope with the extra electrical load.

[trace1967]

I have an aircon button off but no aircon in the engine.
Turn the heater knob to 1 and it revs up.

[Richyvrlimited]

trace1967 said:

Happens with mine and I dont like it as I keep thinking its using too much fuel. It goes up then drops down but not back to the original revs when its idling without the heater on.
Is this normal??

Yes it's normal and the amount of extra fuel used is minuscule. If you're that worried over consumption I hope you never open any windows (uses more fuel just opening them never mind the extra drag once on the move!) drop the roof, tun the stereo on, charge an accessory etc etc etc.

[MX-5 Lazza]

When do you ever turn the fan off anyway? Mine never goes below 0.

[Gizmo!]

MX-5 Lazza said:

When do you ever turn the fan off anyway? Mine never goes below 0.

Mine neither - if I don't want face-air it goes on the windscreen setting.

The OH always used to turn hers off though, until I pointed out it was better for the air-con always to leave it flowing...