Larger engines (such as those in power plants) are also generally more efficient. And RVs don't use oil to drive the oil to where the car can get oil - we have the grid (a modern wonder of the world) to do that for us.
Larger engines (such as those in power plants) are also generally more efficient. And RVs don't use oil to drive the oil to where the car can get oil - we have the grid (a modern wonder of the world) to do that for us.