Tomorrow it will be a month since I last filled up the car with petrol. The tank is almost empty now; I’ll fill it up again tonight.
Generally I just fill it up when it’s getting lowish and it’s convenient. Given my consumption isn’t high, I don’t bother to shop around, and if I see the queue is long, I look for another petrol station.
My new car is more efficient than my old car. I know this because while both have about a 50 litre tank, I used to fill up the old car with petrol about every 2-3 weeks; now it’s about every 3-4 weeks, and the amount of driving I do is roughly the same as it was then.
Another totally unscientific measure of consumption: I reset the tripometer the last time I filled up. Based on how far I’d travelled by the time it got to half-full, then quarter-full, and now almost empty, I can drive about 500 km on a 50 litre tank, which seems pretty good.
Mind you, that makes 10 litres per 100 km, which is a fair bit above the theoretical 7.6 figure in the Green Vehicle Guide. (I had to use the Astra Classic figure, as the GVG only covers post-2003 cars, and annoyingly the older Fuel Consumption database at greenhouse.gov.au has gone offline.)
I guess that means that (a) theoretical figures are just that, theoretical, and (b) I can probably learn to drive more efficiently.
Update Thursday night: Of course, my relaxed petrol buying strategy means I paid 10 cents per litre more today than I would have done yesterday. Mind you, long queues yesterday, none today.