i use e10 tanks to, like chinyoti.
Have, ever since i bought the swift.
Yesterday got 1500 ka e10 and 1500 ka normal petrol.
Acceleration was notably reduced, owing to the higher octane rating of e10.
Havent yet checked performance yet, but e10 has given me as much as 600km per 40 litres, and as low as 450km per tank too when i drive aggressively.
So mileage stays between 11km/l and 15km/l.
Havent yet checked the performance of normal petrol ki addition of fuel efficiency though