Fuel mileage with the Idle Stop Function

Idle Stop	Odometer Start(km)	Odometer End(km)	Fuel(ℓ)	Fuel Mileage(km/ℓ)
off	4466	4839	15.27	24.43
on	4839	5194	14.75	24.07

After an accident that left my rental Daihatsu Move dented, the rental car company replaced it with a Suzuki Alto. That was the first time I saw a car with idle stop function. However, in my thought, it is not so suitable for brief stop. It is only a 15 minutes ride to my work place, and there are lots of traffic lights, the stop usually won't last more than one minute. On off engine will use more fuel in a short span of stopping time. To test it out, I decided to count the fuel mileage.

I filled my gas tank full after I jot down the reading on the odometer. Did it twice, once with 'idle stop function' off and another on. However, I was surprised that it doesn't change much. Maybe the sample size was too small. Anyway, that's it. This experiment ends now. To get an accurate result, I refrained myself to switch on the heater, it is damn cold now. (I started this during September, the weather was nice, not too hot, not too cold, so I didn't switch on air conditioner!)

Top: Suzuki Alto dash board on the top (the engine signal is cold)
Below: the Idle Stop Function Switch