Have a 1994 VX, rebuilt the engine and enjoyed about 50MPG on a highway trip doing about 70-80mph and a 65mpg going about 65mpg. In town it only gets about 38mpg, a bit of a lead foot.. I took 2 100 mile trips and was disappointed to find out that I was getting 38mpg! and I was doing the 65mph all the way on both. It seems to be stuck at that mpg no matter how I drive now. Any thoughts?