Well......as far as I know.......you need a break-in period for each car.........not necessarily the engine only.......you need to be little careful with brakes.........avoid high acceleration........sudden braking.....avoid constant speed for too long........and if possible short trips.........this doesn't mean that you need to be too slow........these engines are meant to be tough and you can be tough with these..........just avoid abrupt change in speed...........
I am sure there are Pakwheelers who can add to this