I'm currently at 79 000KM and 11.6L/100KM. Tufoil is an oil additive used here by the canadian government in their trucks and vehicules all year long. They claim that they saved 5% in gas and 30% time getting the motor ready in winter. Anyway, i buyed it today and will try it for the winter. I'll post here the results next week and after a month. You will be able to make your own idea.

11.6L/100KM = 20.25MPG FYI. Mostly city driving.