Corporate Average Fuel Economy
From DDL Wiki
Corporate Average Fuel Economy (CAFE) is the required average fuel economy for a vehicle manufacturer's passenger cars and light trucks with gross vehicle weight rating (GVWR) of at most 8,500 lbs each year. CAFE values from determined fuel economy estimates are combined with results from city and highway tests administered by the United States Environmental Protection Agency (EPA). EPA also determine the procedures for calculating the fuel economy values for CAFE. The National Highway Traffic and Safety Administration (NHTSA), which is part of DOT, is responsible for establishing and amending the CAFE standards for trucks. Manufacturers’ annual CAFE results are reported by EPA to NHTSA, who then determines if penalties are required. [1]
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Calculation of CAFE Estimates
Vehicles are tested in two different situations: city test, where cars are driven for 11 miles at 20 mph, and highway test where cars are driven for 10 miles at 48 mph. The emissions results are adjusted to account for conditions that occur in real life, such as extreme temperature, aggressive driving, power-hungry accessories usage, etc. City results are adjusted down 10% and highway results are adjusted down 20% accordingly. Carbon compounds expelled in the exhaust are then measured and formulated into a carbon equation, which are then used to calculate fuel economy estimates from adjusted emissions. More information on calculation of CAFE estimates can be found on the EPA website.
CAFE Policy on Trucks
CAFE has a separate policy on trucks. A truck is defined as a vehicle that has 4-wheel drive or is more than 6,000 lbs. GVWR. Light trucks that exceed 8,500 lbs gross vehicle weight rating (GVWR) do not have to comply with CAFE standards (i.e. pickup trucks, sport utility vehicles and large vans). The current CAFE standard on trucks is to have a minimum fuel economy of 21.6 MPG. In March 2003, CAFE standards proposed for fiscal year 2007 was 22.6 MPG. However, a new average was proposed in March 2006 that the new average will be 24.1 MPG. As of now, the penalty charged per truck per MPG is $55, which is the same as small-medium sized cars. This amount is subject to change.
CAFE Incentive for Alternative Fuel Vehicles
CAFE incentive policy
- Alt fuel vehicle: FE = FEorig/.15
- Duel fuel vehicle: FE = 1/((.5/FEconv_orig)+(.5/FEalt_orig))
- Natural gas: FE = FEorig(100/.823)(1/.15)
- Energy: 100 ft^3 natural gas = .823 gal gasoline
- Volume: 1 gal natural gas = .15 gal fuel
CAFE Credits
* If fuel economy of fleet exceeds established standards – get credits
* Credits can be applied to any 3 consecutive model years immediately prior to or subsequent to model year in which credits are earned.
* carry back credits – credits applied to prior years
* If there are not enough credits available, then the manufacturer can either pay the fine, or submit a carry back plan to the agency
* (FECAFE - FEMANUF) * 10.0 * cars = total credits needed
* carry forward credits – credits applied to subsequent years
* If credits not used within three years, they are forfeited
* Credits cannot be passed between manufacturers or fleets (domestic light trucks)
Calculating CAFE Estimates
* Test vehicles in two difference situations: city test (11 miles at 20 mph) and highway test (10 miles at 48 mph)
* Adjust emissions results to account for conditions that occur in real life (extreme temperature, aggressive driving, power-hungry accessories usage, etc.)
* City results – adjust down 10%
* Highway results – adjust down 20%
* Carbon equation: measure the carbon compounds expelled in the exhaust and calculate fuel economy.
* Calculate estimates from adjusted emissions using carbon balance equation.
* FEave = (total sales / [(sales1/FE1)+ (sales2/FE2) + ...+ (salesn/FEn)]
* FEcomb = 1 / (( .55 / city FE) + (.45 / hwy FE))
Calculating CAFE Penalties
Small-Large cars
Conventional
Alternative Fuel (any type)
Dual Fuel (any type)
Natural Gas
Light Trucks
Conventional
Adding on Credits
