Also, do the pumps there adjust for ambient temperature? In Canada, gas pumps have a sticker that says something to the effect of "volume corrected to 15 C". When it's as bitterly cold as it has been the last few days, the gas can become denser, so 10 L in the tank may actually be 10.3 L on the pump (because if that gasoline started at -15 C and warmed up to 15 C, that's the volume it would expand to).