For your consideration:
Back in 1999 I got a pickup truck. I bought two 1979 Chevy 1500 pickup trucks, neither of which was running.
I bought new mounts, took the bed from one and the cab from the other, ground out the rust, had a friend weld some new metal where it rusted, and put on two coats of primer. I had the smallblock 400 partially rebuilt, and installed a manual transmission that I got from that garage that they had torn from a wrecked vehicle. I scavenged the junk yard for additional parts, and used what I could off the two salvage trucks. Mechanically, it was restored to new condition. Everything mechanical was rebuilt, and consumables like cab and bed mounts were the only new parts.
Maybe it got 16 miles to the gallon. When I completed it it had 76,000 miles on it. I sold it with about 125,000. I used it in snow, to plow and to haul, and do other heavy work. I lent it to whoever needed it. It cost me about $2200 to make and I sold it with plow for $1,000. I know for a fact it’s still in service.
There were many many times when I just drove the truck for the hell of it, sometimes on trips. I wasn’t making use of the bed or anything. Let’s say half of those miles were like that, when any vehicle, particularly a more fuel efficient vehicle would have sufficed.
Now, I beleive, and would like to argue that that truck was more efficient and green than any new vehicle I could have bought. I would go further and argue that if all I did with it was commute and never used it for utility it would still have been more efficient.
Let’s say I had bought a Prius. There would have been one new vehicle on the road. The demand for new vehicles would have increased by one. Instead, every single resource in that vehicle was recycled to the extent possible instead of junked.
The manufacturing savings in driving a recycled/rebuilt old vehicle no matter how inneficient it was far exceeded the MPG saving available had a new. albeit extremely efficient vehicle been purchased in its stead. This would be true even if I had driven it 100,000 miles.
Is this in fact accurate?
I am trying to cultivate an environmental ethic as follows: I hate this disposable culture where we always get new stuff. When I buy something now, I look to try to buy the last thing of that kind I will ever need to buy, or at least the most durable. This is sound environmentalism.
For example, the WOLF Stove I own is not the most efficient. However, I have the expectation that it will last as long as I own and live in my house.
I bought a brand new Kubota tractor. It was expensive and not all that efficient, but I have the expectation that it will outlive me. My previous tractor was built in 1948 and I traded it not because it was worn out but because it’s high center of gravity made it unsuitable and dangerous for my current home. Somebody else is using it now. While neither is particularly gas efficient I think they make up for it in their durability. They don’t need to be replaced.
I don’t think we can consume our way to environmental nirvana any more than we can drill our way out of an oil shortage.
With cars for example, I think that we are unduly focussed on MPG. While important that ethic fails compared to the environmental cost of manufacturing a new vehicle.