An Interesting Extrapolation

I was talking with my dad the other day while he was shuttling me back to Purdue about his recent increase in mileage. He drives a Prius, and was always aggravated that he couldn't get the 50 mpg on the highway that the commericals tout. He wasn't getting 61 mpg in the city, either, but attributed that to not accelerating like a sloth. Anyway, he figured that the highway mileage was for highway speeds, but could only manage about 42 mpg while on the highway.

With the recent spikes in gas prices, though, he decided that it wasn't worth speeding anymore. Note that when I say recent I'm referring to $3.50/gal and above, so quite recently. The fact that people would do nearly anything for $2.00/gal gasoline is laughable, exposes our complete dependency on automobiles, and should be reserved for another post. So, upon reducing his speed on the highway to the posted speed limit, my dad realized that the 50 mpg milestone was consistently reachable. This realization led me to do some quick math, which is the cornerstone of this post and provides a method of reducing our dependency on foreign oil.

Dad's increase from 42 to 50 mpg is a whopping 19%. I'm not sure how much of that increase can be attributed to new technology, but I'll say 7%. Given that the average age of cars on the road is about 8 years (from a quick online search) and that cars in 2000 didn't have the gas saving technology of cars in 2006, 7% sounds reasonable to me. Also, presuming that 30% of all drivers religiously obey the speed limit and the other 70% could get a 12% boost in mileage by slowing down, this gives an average gas savings of 8.4%. This means that 11/12 of the current U.S. gasoline demand would be sufficient. In other words, at the current rate of purchase, the U.S. government could tell the Middle East that we don't need any oil for an entire month.

If only enough people cared.