What in the hell is petrol?voxmagna said:I think I actually get better fuel consumption because I ride slower, less often and more carefully due to variations on road surface conditions.
Fuel injection atomises liquid petrol. Cold denser fuels and engine can produce larger drops in the injection spray pattern and richer mixtures reducing combustion efficiency. Also the motor will be running richer for longer until the ECU picks up the design engine temperature to lean off the mix. Very cold water in the jackets and rads will also take longer to reach normal operating temperature. My temperature guage consistently reads a bit lower in Winter but I think this is down to the rad sizes, coolant volumes and thermostat bypass effectiveness. The inlet air temperature sensor should also be compensating for cold air. I'd expect compensation to be towards rich rather than lean, because poor combustion with a weak mixture usually produces erratic idle and stalling which we'd all notice. Driving the bike regularly from a heated garage on really cold mornings might be interesting. How does the motor run in the first few minutes?
I like this answer best. Oxygenates have fewere BTU's (energy) than normal gasoline components, thus the same gallon of gas has less energy. Your bike is using the same energy, it just takes slightly more volume to supply that energy.bertbrumfield said:All this sounds verry scientific and I am sure that it all has a real effect on gas mileage.
BUT, and a very big but, the gas [petrol??] companies change the formula of their product at different times of the year and this will have the biggest affect on your mileage. In my state, [north carolina] the past several years, oxigenated [sp?] gas has been mandated for the colder months and results in about a 10% drop in fuel mileage.
I suspect that the blend from the gas coompanies will have the giggest affect on your mileage.