There’s a decade-old Washington State report (“Washington Tax Structure Study SIMTAX”, Washington State Dept of Revenue Research Division, Oct 1 2002) that says: “The business-household split for the motor fuels tax is based upon gasoline purchases published in National Transportation Statistics. Autos and half of small trucks are assumed to be household and the rest business-owned. Implan data implies that state and local governments purchase just under one half of one percent of refined petroleum products, so the government share is assumed to be zero.”

(BTW, it also says “Sales and use taxes are attributed to the business, household, and governmental (state and local) sectors based on input-output data from the Washing Implan model… The results indicate that households bear 60% of the initial incidence of sales/use taxes, with the business share 32%, and state and local government share 8%.”)

Now, National Transportation Statistics 2011 shows:

  1. Table 4-9: Motor Vehicle Fuel Consumption and Travel: Motor vehicle fuel consumption totaled 168.6b gallons in 2011. Average vehicle in 2011 traveled 11,600 miles, got 17.5mpg, and used 666 gallons of gasoline.
  2. Of the 168.6b total gallons, Table 4-10: Estimated Consumption of Alternative and Replacement Fuels for Highway Vehicles estimates 135b was gasoline and 39b was diesel. (These numbers also include some biofuels.)
  3. Table 4-11: Light Duty Vehicle, Short Wheel Base and Motorcycle Fuel Consumption and Travel: Light-duty vehicles with short wheel base consumed 88.5b gallons of fuel; on average they traveled 10,600 miles, got 23.1 mpg, and used 460 gallons of fuel. (I’m ignoring motorcycles.)
  4. Table 4-12: Light Duty Vehicle, Long Wheel Base Fuel Consumption and Travel: Light-duty vehicles with long wheel base consumed 35.3b gallons of fuel; on average they traveled 14,600 miles, got 17.1 mpg, and used 855 gallons of fuel.
  5. Table 4-13: Single-Unit 2-Axle 6-Tire or More Truck Fuel Consumption and Travel: These vehicles consumed 15.1b gallons of fuel; on average they traveled 13,500 miles, got 7.3 mpg, and used 1,834 gallons of fuel.
  6. Table 4-14: Combination Truck Fuel Consumption and Travel: These vehicles consumed 28.2b gallons of fuel; on average they traveled 66,800 miles, got 5.8 mpg, and used 11,500 gallons of fuel.
  7. Table 4-15: Bus Fuel Consumption and Travel: These vehicles consumed 1.9b gallons of fuel; on average they traveled 20,700 miles, got 7.1 mpg, and used 2,900 gallons of fuel.
  8. Now, add up #3-7 and you get a total of 169b gallons, which matches #1 and #2.
  9. PS. Note the important footnote in all of these: “Data for 2007-11 were calculated using a new methodology for light duty vehicles and motorcycles developed by FHWA. Data for these years are based on new categories and are not comparable to previous years. The new category Light duty vehicle, short wheel base includes passenger cars, light trucks, vans and sport utility vehicles with a wheelbase (WB) equal to or less than 121 inches. The new category Light duty vehicle, long wheel base is found in table 4-12 and includes large passenger cars, vans, pickup trucks, and sport/utility vehicles with wheelbases (WB) larger than 121 inches. This edition of 4-11 is not comparable to editions from 2009 or earlier.”

Other random facts from this report:

In Washington the state Dept of Licensing oversees the collection of fuel tax, including:

  1. the tax on motor vehicle fuel or special fuel (37.5 cents/gallon), which covers gasoline, diesel, ethanol, and biodiesel but not dyed (farm) diesel; Brookings estimates this at $1.2b in 2010, i.e., 3.2b gallons per year in 2010.
  2. the tax on aircraft fuel (11 cents/gallon), with revenue estimated at $5.6m for the 2011-2013 biennium, i.e., 51m gallons per biennium or about 25m gallons per year; and
  3. the tax on heating oil (1.2 cents/gallon).

WSDOT also has county-by-county estimates of transportation taxes paid.

Kean et al. (“A Fuel-Based Assessment of Off-Road Diesel Engine Emissions”, Journal of Air & Waste Management 50: 1929-1939, 2000) has Table 1A indicating that in 1996 Washington State had total distillate fuel oil sales of 3.02b liters (800m gallons), of which 1.81b liters (60%, or 478m gallons) was on-road, i.e., was taxed for on-road use; 0.16b liters (5%, or 42m gallons) was farm; 0.11 (4%, or 29m gallons) was construction; and total off-road equipment (including farm and construction) was 0.47b liters (16%, 124m gallons). The remainder of 0.74b liters (25%, 195m gallons) includes home heating oil and other RCI. Total distillate fuel oil sales of 800m gallons in 1996 seems approximately correct given total U.S. consumption of 39b gallons of diesel in 2011 since Washington State is about 2% of the USA. Also, the 2008 WA GHG Inventory lists 9.2MMTCO2e of “onroad diesel”, and 9.2MMTCO2e is about 1b gallons. So as an approximation, farm diesel amounts to about 10% of on-road (taxed) diesel. EIA estimates 1.0b gallons of transportation diesel in WA in 2008, so 10% would be 100m gallons for farm use in WA.