[Perfectlap]

Necessary? Well to reduce the engine wear and promote longevity I think you'll find the lower RPMs you run the longer the engine will last.
Whenver I upchange to 6th gear on the highway the revs come down. May or not be the best for the fuel consumption but its easier on the engine life me thinks.
When I commuting in city traffic I keep the at 3rd and 4th to strike a good balance.

I also try to short shift in the winter as much as possible before the oil temp is in the safe zone.