Tuesday, April 18, 2006

Short Environmental Thoughts

There are two things that are bothering me right now that I think could be fixed rather easily by just a little bit better legislation.

One is the use of E-10 or 10% ethanol. Only 40% of gas in the U.S. uses it. I really can't see any justification in it. Not only is E-10 totally compatible with all vehicles, and everything I've seen shows it's a fair bit more economical then gasoline. Ethanol itself is slightly cheaper on a volume basis than gasoline, but E-10 actually gets better gas mileage than pure gasoline. At higher mixtures ethanol may produce lower mileage, but at 10% the benefit as an octane enhancer usually outweighs the loss in stored energy. The reduction in knocking conserves burns all the fuel more cleanly and produces more power and less pollution.

I would like to see more states adopt E10 regulation. Honestly the oil companies should be using it today, but apparently they are more concerned with the long term reduction in oil demand then they are with the short term costs. Illinious has a law, not specifically about E10 though. The link above has a better list of the very very few states that are doing anything about this.

The second thing is the way that federal fuel economy laws work. As a basic overview, vehicle manufacturers are required to produce vehicles that meet a certain average in MPG or pay fines. The problem lies in MPG and the fact that this measurement is very bad when used as an average. The problem is that a 10mpg slug and a 60mpg hybrid average to 35mpg, yet the combination of those two both driving an average of 10,000 miles per year will burn alot more gas than two 35mpg cars.

(10,000/60)=166.6 gallons, (10,000/10)=1,000 gallons. 1,166.6 gallons.
(20,000/35)= 571.4 gallons.

The result of this is that every consumer that buys a 60mpg car is in effect enabling the vehicle manufacturs to sell a car that will consume an extra 500 gallons of gas every year. I doubt this is what that consumer intended. If however he had bought a 35mpg car, then maybe one more SUV driver would be forced to buy a 35MPG car. Or at the least maybe that vehicle manufacture would have to spend an extra $50 on that SUV to make it get 11mpg which would save 92 gallons of gas.

The fix? Laws should be based upon an average of gallons per 1000 miles. In this scenario the very bad are punished far more severely.

60 mpg becomes 16 gpkM, and 10mpg becomes 100 gpkM. The average, 58gpkM converts to 17mpg, a far less attracive total, and a point at which fines would be imposed. Of course two 35mpg cars still average 35mpg.

I guess the best thing to do is write your legislature, something I don't do very often, but plan to do this time.


Anonymous said...

My understanding is that CAFE does not use the arithmetic mean but the harmonic mean. This already accomplishes what you want.

See the Wikipedia entry on CAFE: http://tinyurl.com/k5qu8

Ryan Baker said...

Thank you, you are right, I missed that important point.

Still I think it would be more beneficial if we switched from mpg listings to gpm or gpkm listings because it would be far more clear how severe the difference is between a bad car and a really bad car.