My Xebra sedan has done 7,000 miles, I can get about 43mph on the flat using a 7th 12V battery. A better question than the one above would be: "how fast can you go up the 3% grade at the end of 40 miles?" You only get a certain amount of energy out of batteries, regardless of the vehicle specs. The Xebra is doing far better than a C5, for example. To compare it with a gas powered car isn't useful. It is what it is, or what you can "modify" it to be.