First the car engine and thus the air conditioning compressor are running faster at highway speeds, so the unit is capable of more cooling. Second highway speeds force more air over the condenser...
You get farther on a gallon of gas when driving on the highway, than when you drive in the city. This is because in the city you have more stop and go situations that are wasteful. The solid proof...
City driving is ; driving at slower speeds, stopping at various stop lights, sitting at stop lights.
City driving (as opposed to highway driving) is considered harder on the car, it wears out...
Overdrive is the normally allowed position , but unless you are going fast enoughit will not shift into overdrive because it acts as the " top " gear ( on my Explorer Ihave to be going 50 miles per...