According to The Wall Street Journal, lenders are considering using price optimization, the same system airlines, hotels and other industries use to charge customers different prices for the same product or service.

In the past, borrowers with the same credit score, and applying for the same type of loan, would have been quoted the same interest rate.

But price optimization software tells lenders which customers are more likely to accept higher interest rates.

It's found, for example, hat borrowers who apply for a loan in person are more willing to pay more than those who apply over the Internet, and those who live in small Midwestern towns are less price sensitive than those who live in New York City.

Using banking preference and geographical information, the system can produce different rates for 20,000 customer groups.

Banks are understandably reluctant to say if they're going to use that data to price mortgages and other consumer loans.

But the Journal reports that Wachovia and Washington Mutual are already using it to quote home equity rates.

Atlanta-based SunTrust used the software in the past year to determine when it may have charged people less than they were willing to pay for an auto or home equity loan.

Bank of America has tested it on mortgages while Motor Credit and AmeriCredit set car loan costs using price optimization, the Journal says.

All of this makes it even more critical to shop around, and shop smartly, for the best rates. Here's our step-by-step advice for getting the best car loan and mortgage.