This is something that fascinates me. How much "should" something cost? I once had a teacher say that a thing is worth what it costs to replace it. That was long before the "sustainability movement" (is there such a thing?), but one implication is that things need to be recycled to be cheap, and that irreplaceable things are expensive.


To follow the logic, a gallon of petroleum can be replaced with a gallon of other things, none of which are "cheap". Petroleum has been the Wal-Mart solution to our energy needs for about a hundred years. Prior to petroleum, personal transportation was a rare luxury. Horses needed to work for a living, so they weren't common unless you needed one for your work (cowboy, for example). If you wanted to travel to a distant town, and didn't have your own horse, you took the stage or train. Both would now be considered "public transportation" and were subsidized. Now our cities and houses are designed assuming cheap individual transportation, and we've forgotten cars should be considered "luxuries" unless they work for a living, like horses did.

My 70-mile commute round trip constantly reminds me how unsustainable my working arrangement is. I couldn't afford acreage closer to work, but this would be impossible without a car.

So, what price is too high? My wife and I once figured that when my commute reached the breaking point, I'd find an apartment close to work. Commute costs would then drop to near zero (bicycle). The point is that my commute is "worth" what it would take to replace it: living within bicycling distance of work.

Let's say I found a cheap apartment for $600, which with utilities brings it to about $700/month. I attend work 20 days/mo, so my 70-mile commute is "worth" $35/day, or $0.50/mile. The Jetta gets 45 mpg, so a gallon is "worth" 45 x 0.50 = $22.50.

Assuming I've lost you by now, that means it's cheaper for me to commute as long as my fuel remains below $22.50/gallon.

It also means that public transportation is a good idea. Too bad we don't have any, but I predict that will change.

It's intuitively obvious that cars that get good mileage are best for long commutes. Biodiesel has the advantage of being used by some of the best mileage cars around. Ethanol actually suffers from the opposite problem - all the GM E85 flex fuel vehicles suck gas at a prodigious rate.

Cheers,
JohnO