My IS has 7500km on the clock and I get 11.5 L /100 kms.Our best petrol is 95 octane .I don't know what this is in gallons per mile.I also don't know if my figures are any good.Quite frankly I don't really care.I do know it is far better than most of the yank tanks around .
Anyway ,if anyone can convert for me ,Thanks