Monday, August 04, 2008
Fuel Efficiency
UPDATE: This includes "Distillate Fuel Oil", which includes diesel, as well as gasoline. The data is very noisy because the Distillate Fuel Oil data includes Distillate Fuel Oil used for power generation, locomotives, and construction and industrial equipement. A large portion of the consumption does not correlate with miles driven, so it masks the trend.
The trend is much clearer when miles driven are compared with gasoline consumption only. This ignores that diesel use for commercial transportation could be up, diesel use could have improved in efficiency (congestion on interstate roads is down), and maybe only car travel is down. However, from a 2005 BTS study, commercial diesel vehicles only makes up ~7.5% of vehicle miles travel, diesel commercial vehicles only get 6-7MPG, and efficiency gains are not likely to be large.
