I'm guessing that this might be a stupid question, but I'll ask it anyway, as I really would like to know the answer ...........

Since the cold weather has started here in Vienna I've been using my hot grips every day and together with my Italian hand muffs, they are by far the best extra I've installed on the SW. However, I've noticed quite a drastic reduction in my fuel economy since this time!

So, does the use of heated hand grips cause this extra use of fuel in much the same way as I believe that air conditioning does on a car??

Or does the cold weather alone cause a poorer fuel economy?

Just thought I'd ask

SteVe

Steve,

One way you could see if the heated grips being on make any difference to your fuel consumption is to do two exactly the same rides, Fill the tank up before each ride, ride without grips on, fill tank and see how much fuel you have used. Repeat process with grips turned off.
Either that or just grin and bear the the price of the extra fuel.

Cheers,

In my experience, the SWing uses more fuel in cold weather.

No question my fuel consumption has gone up as it has gotten colder - among other reasons, stays on fast idle longer as it warms up.

The Swing engine seems to do best at higher ambient temps (25C-35C).
Whether it's a function of the ECU programming or increased friction (higher drag from denser air, increased rolling resistance, more viscous oil) or all of the preceding, the Swing definitely consumes more fuel when it's colder out.
I would think a dyno would show more power as the temp falls due to denser air requiring more fuel. Increased O2 and increased gasoline means more power!
The increased wattage required by the heated grips wouldn't cause any measurable increase in fuel consumption. Yes, the rotor would be harder to turn inside the stator due to the increased magnetic field required to generate more electrical output, but it would be negligible. A/C in a car can suck 10-20HP. 100W of electrical power requires roughly 0.15 HP (100/746), 746 being the hypothetical number of watts in 1 HP. Your road friction of running both tires 2 lbs low would cause much more power loss than heated grips.

Steve:
I have noticed a drop in my mpgs every year when the weather turns cold. In summer I average around 55 mpg. The last couple of tanks I have been just over 50 mpg. It could be the gasoline formula we are forced to use. In colder weather they switch to an oxygenated fuel (10% ethanol) I'm not sure if this is the reason or if it is a combination of the factors listed by others above. All I know is that my mpgs drop in cold weather. I wouldn't think that the hand warmers would have anything at all to do with the drop in mpgs that you have noted.

Thank you everybody for enlightening me on this topic.

Must remember to check my tyre pressures next time I stop for fuel, as this seems to be crucial to fuel economy!

SteVe

Tire pressure does drop with colder temps.

I believe that MPG drop is due mainly to the incoming air temp to the engine. There is a fuel enriching circuit that dumps more fuel when you start a cold engine. (fuel enriching circuit)
This is influenced by air temp going into the motor. The colder the air the more fuel is used.
This in conjunction with winter gas mixes, will cause a loss of MPG's.

MaxB(who's air temp gauge is his fingers getting cold and stiff)