AutoblogGreen reader Michael recently sent in a question regarding the about-to-start "Cash for Clunkers" program. Officially known as the Car Allowance Rebate System (CARS), the program allows owners of some older and inefficient vehicles to trade them in and get a rebate check worth up to $4,500 from the government to buy a new car. The simple version of the rules are that the trade-in can't be more than 25 years old, needs to have an official combined highway/city fuel economy rating of 18 mpg or less (on the EPA's new mpg scale), be in drivable condition and you have to have owned and insured the car for at least the year prior to turning it in. Michael's question revolves around what happens when a car has two fuel economy ratings - one for gas and one for ethanol. Turns out, no one really knows yet. Find out more after the jump.

Photo by iboy_daniel. Licensed under Creative Commons license 2.0.

Michael's email read as follows:


I own a 2000 Ford Taurus Flex Fuel auto. The combined mpg for unleaded gasoline is 20mpg which is over the required minimum of 18 combined mpg for the cash for clunkers program. The E85 combined mpg is a combined 15mpg which is under the minimum of 18mpg combined. Is this vehicle eligible for the program?


We thought the answer would be no, the vehicle is not eligible, because CARS only counts the fuel economy number when using gasoline. The CARS FAQ page explains the qualifications this way:

How do I find out the combined city/highway fuel economy rating of my trade-in vehicle?

Go to http://www.fueleconomy.gov/feg/sbs.htm and click on the model year of your vehicle, the make, and then the model. Under the words "ESTIMATED NEW EPA MPG" in the red banner, there is a red number with the word "COMBINED" under it. That is the new combined city/highway fuel economy for your vehicle. You may then enter the make, model, and model year of a new vehicle you may want to buy and see its combined MPG for comparison.

When you follow the instructions, you see an image like the one above. For most vehicles, there is only one number that gives the gasoline rating. If that's under 18 mpg, then you're good to go. But, in Michael's particular instance, there are two ratings, one that would qualify and one that wouldn't.

We called National Highway Traffic Safety Administration, the organization responsible for implementing CARS, to get to the bottom of the story. The NHTSA representative we spoke to told us - repeatedly - that, if you claim that you've been using ethanol in a trade-in car that has an E85 rating that qualifies for the rebate, then, yes, you can get the multi-thousand-dollar voucher towards the purchase of a new car.

The bill authorizing CARS is H.R. 2346, which President Obama signed in late June, and the text describing the program can be found here. In this legislation, there is no mention of ethanol or a particular fuel type. Instead, it reads:

With respect to a new fuel efficient automobile, the number, expressed in miles per gallon, centered below the words `Combined Fuel Economy' on the label required to be affixed or caused to be affixed on a new automobile pursuant to subpart D of part 600 of title 40, Code of Federal Regulations.

Here's what the label looks like:



The EPA's regulations on how to come up with this number stipulate that it must "indicate the fuel economy of the automobile when operated on gasoline or diesel fuel." Therefore, we're pretty sure that CARS will only look at the gasoline number, and our friend Michael is out of luck if he was hoping to trade in his Taurus. Things could change, of course. The EPA told us that no one really knows yet what the rules are, because they are still being drafted. According to the Department of Transportation, the full rules of the program will be made public in late July. Stay tuned.