There is no big difference in both, what i do is keep changing the petrol form super to special
One word of advise avoid refill from anywhere but eppco and enoc as they have the finest petrol comparatively
Nazii
Faced same problem. all gears work well except Parking, what i did was drive down to a near by mechanic and he fixed in one hr.
the problem was a broken linkage from the shifter to the transmission which was one of the cheapest fix till date.