Friday, March 17, 2006

California Gasoline

The BTS uses 124,700BTU/gallon of regular (unleaded) gasoline in its' national energy calculations. [N.B. Lead is immaterial
regards energy content.] Unfortunately, Kalifornia with our 13% of the entire population and over 15% transportation share doesn't get "real" gas. We get liberal gas. Pun intended. You know why Kalifornia gas generates 10% less pollution? Yep,
because Kalifornia gas has 13% less energy content. Rocket science. The difference is made up with oxygenates and nonenergy content additives. For the less technical, oxygenates are air. Yep, what grocery stores do to ice cream, Kalifornia does to gasoline; fluff it up with air. Do this with ice cream and the District Attorney prosecutes. Do this with gasoline and you get to charge EXTRA for the effort involved. This does reduce certain bad byproducts such as NOx but it also increases the two major greenhouse gases H2O and CO2. Diesel is not affected by the Kalifornia oxygenate regulations. The BTS does not prorate but uses the FTA, APTA, FHWA and other sources for diesel.

The result is; were we to prorate for actual Kalifornia efficiency rather than the assumed efficiency would be another 15% advantage to POV autos over others on specific energy consumption.


Anonymous said...

Ok Robert, that is actually pretty fucking interesting. But, being as I am an engineer but not of the specialty you speak of, answere this in plain english, please:

Are you saying that my gas mileage would increase by 15% running petrol purchased in Nevada?

Rob Dawg said...

Collectively yes. 1-3 more mpg depending on vehicle and driving habits. There's more energy useable for moving the car in Nevada gas than in California gas. Near as I can tell Calgas is about 112k BTU/gal. That's about 12%. It isn't a straight 1:1 correspondence for every vehicle in every case due to ephemera such as compression ratios, vapor volitility, etc. but it works out to a noticeable difference. The 15% instead of 12% is because most engines are designed for 124.7k BTU/gal fuels.