So 4 days back i Installed Continental cc6 tyres in my Yaris Ativ x in 185/65R15 size and i noticed that.
My Average decreases from 16-17km/L on highway to 12-13 km/L
Also car acceleration is very much affected.
So my advice to Yaris owners is to install oem 185/60R15 size in yaris only.
I am also going to intall Yokohama db decible e70 in 185/60 R15 available in market
These are oem tyres comes in swift.