ooops, I did it again... I'm caught in an endless spiral... I beat all my records with 53.69 mpg (EPA+52.95%) and 760.8 mi. My status for my 1 month history is at +51.79% I realized lately that my cost per 100km is lower than the one of a Prius II at EPA rating : 4.43 €/100km vs 4.89 €/100km ie -9% (here gasoline is 12.5% more expensive than diesel) but I generated 116.5 g/km of CO2 ie +12%. Usually the idiot light switches on & off regularly during 20 mi before staying on. This time it switched on when I started the car this morning and didn't switched off during all the commute. Since 10 days my daily commutes are shorter (9 mi. instead of 20) and as I managed more often the baby during the morning, I heated more the car. This afternoon I had to travel 30 mi to go to a meeting so I didn't want to be out of fuel. For all these reasons I filled up with 14.17 gallons at noon. On the paper the tank is 15.85 gallons so in theory I would have been able to drive another 90 mi... Next time I'll apply the Andrew's "wait... wait... wait..." also when the idiot light switches on Denis.