Stock CG 125 easily gives 50kmpl fuel consumtion if driven at economy speed i.e. 45~55 Kmph. As far as yamaha Junoon & CD 70 are concern they can give ~55kmpl & 65 Kmpl respectiviely if driven @ economy speed The econo speed of CD 70 is 35~45 Kmph whil for junoon it is ~ 50Kmph.
U may not believe but CD 70 can give worst fuel consumption ~ 35 Kmpl if continously driven @ full throtle.
So it tottaly depends on your throttle hand how much average u can get from which bike.