I have to disagree a bit. My wife and I own three vehicles. It used to be four, but her commuter car (Honda Civic) was totalled and we haven't replaced it yet.

By far the most controversial of the three is the 1998 Nissan Pathfinder. This thing is a gas hog and really has no right to be so. It isn't all that big and it isn't all that powerful. But it sucks gas like there's no tomorrow. Why do we have it? Because, in 1998 I needed a 4-wheel drive vehicle and this was the best choice. Since that year, it's mainly just sat in the driveway, ready for road trips for which it's suited. It has less than 90,000 miles on it, despite being 10 years old. And we put 20,000 miles on it in 1998 (it definitely got used).

But I'm not selling it. There's no point. I can afford the insurance and the registration fees and it very occasionally fills a need. It isn't contributing much to environmental damage any more, like it did when it was used heavily and when it was built.

For day-to-day driving, both of us use smaller, more fuel efficient cars (at least when the Honda was still with us and it's fuel efficient replacement will be arriving shortly). The fourth vehicle? A 1989 Toyota pickup with about 210,000 miles on it. Great for the occasional hauling duty. Not selling that either, although I regularly get asked. It was my daily driver until a few years ago.

So why would it be better to get rid of my extra vehicles? To the extent they are used, they keep miles off the daily cars, which makes them last longer. We only drive so much - having additional cars doesn't put more pollutants in the air or burn more gas. It just spreads those things out over more vehicles.