Dear Tom and Ray:

I am currently driving (and loving) my Chevy Volt. So far, I've gone about 2,800 miles with it and used only 19 gallons of gas. And I have not put gas in the car for four months. My question is about driving around town: Can I let the gas run down, and keep only a small amount in the tank to reduce weight and perhaps get better electric range?

-- Maurice

RAY: Well, technically, if you reduce weight, you will improve your mileage. No question about it. Gasoline weighs a little over six pounds a gallon. So you certainly can do that, Maurice.

TOM: SHOULD you do it? That's another question. The fuel capacity of the Volt is about nine gallons. So, say you run it down to one gallon. That saves you 50 pounds in a car that weighs about 3,800 pounds. Round it up to 4,000 pounds with you in it.

RAY: Will shedding that weight improve your electric-only range? Yes, but only by a very small amount -- a fraction of a percent. And while getting a marginal benefit, you risk stranding yourself in some wooded area overnight and passing through the digestive systems of wolves. It hardly seems worth it to me.

TOM: Yeah. I mean, we're all for efficiency, but if you're not careful, you can go off the deep end with this stuff. A lot of people with high-mileage cars seem prone to this sort of obsession.

RAY: For example, once you've shed that 50 pounds of unnecessary fuel, what are you going to do to get the next half-mile on a charge? Are YOU going to lose 50 pounds?

TOM: Are you going to start driving naked to rid yourself of the excess weight of your shoes and trousers?

RAY: It's all theoretically justifiable, but not practically justifiable. After all, you're already getting the equivalent of 93 miles per gallon without doing anything else!

TOM: So if it were me, I'd just enjoy that, and not nit-pick to the point where you either drive your spouse and friends insane, or run out of electricity AND gasoline, and strand yourself. Without your clothes. Good luck, Maurice.