## Archive for June 23rd, 2008

### The Math of Gas

June 23, 2008

TwoPi and I are Live On Location out in California right now, at a giant family reunion. Which is fun both for seeing people and for learning all sorts of new stories about relatives, like my cousin who just got back from visiting Afghanistan (for a month, for fun, just because it was interesting. And in fact it did sound really interesting — he said every single person he met was really friendly, and he didn’t get any negative reaction to being from the US.) (Edited to add: Hey, he has a blog! ) Or hearing about how my uncle-by-marriage and his brother tried three times to do a cross-country road trip by picking up a hitchhiker and taking the hitchhiker wherever they wanted to go on the condition that that person drove while the two brothers sat in the backseat “philosophizing” over a couple of cold ones.

And speaking of driving, Holy Toledo the cost of gas out here is even higher than in New York. Which made me wonder about what the benefits are cost-wise of owning a hybrid. Apparently hybrids are popular enough right now that dealers can charge a little more, either directly or indirectly (by requiring people to buy add-on packages). So here’s what I was wondering:

Suppose that getting a hybrid costs an extra \$10,000 [which I think I read somewhere as a ballpark figure, though I had a hard time determining if it was accurate]. And suppose that a person drives 12,000 miles per year, which I think is roughly what we put on our car. Different hybrids get different mileage (see this site for example), but it looks like on average they might get 20 mph better than our car (around 46 mpg compared to 26).

How long does it take to break even if gas costs \$4.75 per gallon like we’ve seen around here?

Well, in the situation above, we use about 461.5 gallons of gas per year, compared to only 261 on the hybrid. That translates to our spending about \$2,192 on gas, while the lucky hybrid owner would only spend \$1,239. That’s an extra \$953 per year, which is a lot, but if the hybrid really cost \$10,000 more it would take 10½ years to break even. That’s getting close to the life of the car.

Which isn’t to say that hybrids are a bad deal: rising gas prices would drop that 10½ years, as would a lower additional cost to buy a new hybrid, and in any case there are other issues at hand (like simply using less gas). But the numbers suggest that in buying a hybrid it’s worth looking at what the additional cost is, so that the better gas mileage can be put into a proper perspective.