Fuel mileage comparison is quit difficult considering all of the variables involved in such data as fuel mileage. When you speak possible miles per gallon the 100 mpg car seess to automatically come into the conversation with gallon conversion to be realized in fuel mileage. Lets begin by defining what fuel is. My trusty little dictionary says, fuel is anything consumed to produce energy. Energy would be power in action or motion. This motion in the case of a vehicle would be called fuel mileage.
Much of the published information on this subject, of ways to get better gas mileage by car, has to do with hybrid cars, or electric only cars, which are in my estimation a much better way to go, to get a fuel efficiency vehicle . Hybrid cars are not very efficient for fuel mileage, because they have both an internal combustion engine and the electric motor and everything that goes with them both, to make each one function.
The two of these in one car, do add a lot of extra weight to the vehicle, which would have a great influence on the payload of the car. This payload would of course be, how many people it would carry and the amount of luggage etc. This would easily be a big determining factor in the fuel mileage comparison, with other conventional vehicles.
I believe a big drawback to the electric car, is something that I think is maybe more imagination, than fact. That is, the fact we travel and get away from home and our own electric power source, and we are afraid we will get stranded without a charge and dead batteries. Most, if not all of the time that an electric car would need a charge, electricity would be available if we just asked and got more creative, and were truthful about it, with a little planning ahead.
Say for instance staying at a motel, let the management know you will or do need a charge. I would guess, that they would be more than helpful, to let you use electricity for free, or even if you had to pay a buck or 2 or 3, they would love to talk to you about your electric or hybrid car, and the trip you are taking. Another chance for you to have a fuel mileage comparison conversation with a fuel efficiency vehicle person, that cares about his pocketbook and possibly helping the environment.
I feel, the entrepreneurs of a free people, will come through on this challenge, just as it has the development of both hybrid and electric car technology, being just one of the ways to get better gas mileage by car.