bro 125 can give better mileage when u drive it between 50-60 km/h speed with the gear shifting under 5000 rpm.. Bcoz cg is 4 speed bike and it also gives almost same economy as compare to gs in these circumstances , otherwise the economy will decrease...but if we compare cg with gs , gs holds the flat torque and 5speed also ,and gs achieves more speed even if u give light throttle so the economy of gs is better no matter however u drive...