Running in of a car is very similar to anything else with a motor.The valve seats etc are new and need time to bed in,as they wear in they will stretch etc.
Over reving an engine before it has properly been broken in,can cause these materials longetivity to be significantly reduced,and in grim cases the parts can reach their elastic limit/point of plastic deformation and be permantley and damaged or even,fracture.
Take it easy,do not over rev the engine,that said the engine needs to be under load to efficiently be broken in.So pulling a higher gear at low revs can be benifitial,but i recommend this procedure after the car has done a few K's,as the Load can cause problems in itself.
Just putting around will not allow the Engine and other parts of the car to be broken in,the car needs to be driven at a moderate speed and revs,and try not to keep the same velocity and Revs for a long preiod of time.
__________________
Better roads,and better planned infrastructure=higher speed limit  :
|