Has Winterized Gasoline Changed...

[GM1995ES]

...or is this thing finally getting broken in? 95ES with 220K miles (90+% highway). Toyota service throughout its life. For 10 years the mileage was 25-26 mpg, dropping about 1 mpg in the winter. Starting last November, it is now up to 27-28 under the same conditions, and it seems to be climbing slowly. Timing belt (second one), PS pump and O2 sensor in January did not affect the change. Oh, and the same tires (H rating at 32 psi) have been on for over a year, rotated every 5K miles.

[camlex]

NO..Gas is Cheap. Changed 1MPG, I don't care.

[SKperformance]

Your egr valve may be getting stuck open which will cause an increase in gas milage.

I can get about 600 km a tank in my ES with it open but the car has lost some power.

[mburnickas]

...or is this thing finally getting broken in? 95ES with 220K miles (90+% highway). Toyota service throughout its life. For 10 years the mileage was 25-26 mpg, dropping about 1 mpg in the winter. Starting last November, it is now up to 27-28 under the same conditions, and it seems to be climbing slowly. Timing belt (second one), PS pump and O2 sensor in January did not affect the change. Oh, and the same tires (H rating at 32 psi) have been on for over a year, rotated every 5K miles.

winters gas drops mpg by about 10 to 12%