Deeply discounted finance rates have pushed the monthly payments for some new vehicles lower than the average monthly payments for their comparable year-old, used-vehicle twins, a study by Edmunds.com finds.

Take a new 2009 BMW 328i sedan, with an average transaction price of $32,878. According to Edmunds.com, buyers who qualify for the 0.9 percent interest rate offered by BMW Financial Services would pay $560.59 per month or $33,635.40 on a 60-month contract, Edmunds.com says.

Compare that with a one-year-old used BMW 328i with an average transaction price of $29,417. Financed at 10.5 percent — the typical used-car rate calculated by Edmunds.com — the used vehicle would cost $632.28 per month for 60 months, or $4,301.40 more. Neither the new- nor used-vehicle payment calculation includes a down payment.

Rising used-car demand and higher prices, coupled with low new-car interest rates, mean that in some cases, a new car can be a better deal than a one-year-old twin, says Jessica Caldwell, an analyst with Edmunds.com.

"We're telling consumers, 'Don't assume that used is a better value, because that's not always the case,' " she says. "Financing is an issue."

Edmunds.com based its analysis on the new and used vehicles' average transaction prices — called True Market Values — which it compiles by using transaction data from new-car dealerships.

New-vehicle payments were calculated using special finance rates offered by various manufacturers' captive finance companies. Used-vehicle payments were calculated using the average used-vehicle finance rate of 10.5 percent, drawn from data Edmunds.com receives from dealerships.

About 18 percent of new-car buyers qualify for automakers' special finance rates, Caldwell says.  

For its study, Edmunds.com analyzed the prices of every make and model vehicle sold in the United States. Although only a handful made the list of vehicles less expensive to finance new than used, the spectrum spans from BMW 650i convertibles to Honda Civics.

No domestic vehicles are cited because their residual values in general are lower, meaning they depreciate faster, Caldwell says. Audi, Mazda, Mitsubishi and Nissan brand vehicles are on list, she says, because they hold their value well or offer very low interest rates, or both. 

The tax write-off passed by Congress in February and mentioned Monday by President Barack Obama is helping dealers close some new-car sales, says National Automobile Dealers Association spokesman David Hyatt.

The deduction covers the taxes paid on new cars, light trucks, motor homes and motorcycles up to $49,500. Individual taxpayers making up to $135,000 can get the full write off, while those who file jointly can have an income as high as $260,000 to claim at least part of the deduction.

President Barack Obama mentioned the initiative Monday during a discussion on the General Motors and Chrysler LLC bailouts.

"For those thinking about buying a new car this year, this deduction may give them a little more drive to make their purchase this year," IRS Commissioner Doug Shulman said in a Monday statement. "This deduction enables taxpayers to buy now and get cash back later on their tax returns."

The IRS says the vehicle must be purchased after Feb. 16, 2009, and before Jan. 1, 2010, to be eligible.

"I was talking to dealers yesterday about this," Hyatt told Automotive News. "I asked a salesmen if he used the tax write-off as a talking point. He said it was a welcome thing that he's used to close some deals," Hyatt said.

The NADA was instrumental in getting the provision included in the stimulus packaged that passed in February. Hyatt said the NADA may seek to have the program extended by Dec. 31 if auto sales still have not recovered.