The interest rate for a new-car loan at First Virginia Bank is 12 1/4 percent for 36 or 48 months. The rate was incorrectly stated in yesterday's Washington Business section.

The prime rate may be falling, but Washington-area consumers won't be the prime beneficiaries.

The prime interest rate that banks charge their preferred customers has dropped nearly 2 percentage points over the past two months, and most other market rates have dropped a similar amount during the same period as the Federal Reserve has moved aggressively to pump more money into the banking system to end the current pause in the nation's economic expansion.

Two weeks ago, the Federal Reserve lowered the discount rate, the rate it charges on loans it makes to financial institutions, indicating even further drops in market interest rates.

These actions by the nation's central bank have effectively lowered the cost to financial institutions of obtaining money to lend to their customers.

Despite these developments, however, Washington-area consumers should not expect to see any changes in their personal credit lines or credit-card charges, according to a random sampling of banks, retailers and credit-card companies here.

If you're planning on buying a car, taking out a personal loan, getting a new credit card or financing your purchases with Washington-area retailers, your pocketbook may never feel the difference.

"It's rather unfortunate that consumers, by virtue of the public attention brought to prime interest rates, have been put into a mode where they say, 'If that's the prime rate, aren't I prime?' " said Roger W. Conner, spokesman for American Security Bank.

"There is not necessarily any direct correlation between prime lending rates and consumer lending rates," Conner said. "The prime rate is tied to corporate and commercial lending, not consumer credit."

One comparatively bright spot in the consumer credit picture is home mortgages. The national average monthly rate on conventional fixed-rate home loans has been falling steadily since hitting 14.68 percent last summer, according to a weekly survey by the Federal Home Loan Mortgage Corp.

The national average of fixed-rate mortgages had dropped to 13.55 percent as of two weeks ago.

The average interest rate for fixed-rate mortgages in the Washington area appears to be much the same as the national average, according to the latest Peeke Report, which is published by Peeke & Associates Inc. in Gaithersburg.

"Mortgage rates are more attuned to the market," said Bernard M. Markstein III, senior financial economist with Chase Econometrics. "They have started to come down between a half and a full percent age point , and we can expect them to come down another half percentage point from where they are now."

But the story is different for other area consumer loans.

Although the prime interest rate has dropped from about 13 percent to about 11 1/4 percent since September, finance charges for bank credit cards, such as Visa and MasterCard, remain at about 18 percent, as do bank interest rates for borrowed money to cover overdrafts in checking accounts.

Personal installment loan rates generally are frozen at about 18 percent, and area department stores continue to charge their credit-card customers about 21 percent interest on their unpaid balance.

Even so, there is less expensive money to be found if consumers shop around.

For instance, NS&T Bank in Washington offers a 15 1/2 percent interest rate for a 36-month unsecured personal loan for more than $2,000. That represents a drop of 1 percentage point from the 16 1/2 percent rate NS&T was charging six months ago.

NS&T offers a futher 1/2 percent interest break if the bank can collect its monthly payment automatically from a customer's checking account, thereby eliminating paperwork in processing a customer's monthly check.

And while most area financial institutions are imposing a 13 percent interest charge on 48-month loans for new cars, First Virginia Bank is charging 12 3/4 percent for a 48-month loan and 12 1/2 percent for a 36-month loan. But the bank said it will subtract a quarter-percent from the rate for customers with accounts there -- a practice followed by other area banks.

During the Christmas season, Woodward & Lothrop Inc. and the Hecht Co. are offering special credit plans for big-ticket items, agreeing not to begin charging customers for these purchases until February.

Generally, however, economists and bank officials warn consumers not to expect large drops in consumer interest rates. For one thing, they note, demand for credit continues to be so high that banks have no need to lower their rates to attract business.

Consumer credit increased $4.28 billion at an annual rate of 11.5 percent in September, the last month for which figures are available from the American Bankers Association.

Locally, "consumer demand has been pretty strong in the last six months," said Ronald Locke, First Virginia's senior vice president. "Rates would be more likely to drop if there was less demand and a stronger need to entice the customer to borrow," Locke said.

Economists also note that consumers themselves are partly to blame for the higher consumer credit rates.

Despite the differences that exist among financial institutions, "there seems to be less inclination on the part of the consumer to search for the best rates for personal loans," said David W. Berson, senior financial economist with Wharton Econometrics. "They tend to go to a bank where they're already doing business, so it's less necessary for banks to undercut other lenders by cutting personal loan rates."

This factor is even more the case for credit cards, Berson notes. "Typically, an individual doesn't pick a credit card because of the interest rate, but because of where his bank is. . . . In fact, most individuals aren't really aware of their finance charge each month unless they look at the fine print on the back of their bank credit-card statement." As a result, retailers say very few consumers take credit rates into consideration when they shop.

Marlo Furniture Warehouse & Showroom, for example, appears to have one of the highest credit rates in the area -- 24 percent. Yet, notes Marlo credit manager Richard Staples, "the number of cancellations of sales because of the interest rate is very minimal. I would say that, at most, 1 percent of our customers who seek credit cancel their orders after learning of the rate."

Similarly, Scott Parnham, divisional vice president of credit and audit for Kay Jewelers Inc., says, "I quite honestly don't think I've ever been asked what our interest rates are" when arranging credit.

Credit-card experts say that bank credit cards will remain high, noting that credit cards are one of banks' most profitable lines of business.

Additionally, banks say their administrative costs for processing consumer credit are so high that it is not as easy to reduce rates for consumers as it is for their large business customers.

"Our internal costs, including electronic back-office equipment, don't vary as you move from a $3,000 loan to a $3 million loan," American Security's Conner said. "So, to bring parity to that fixed operational cost, our lending rates may be higher for some consumer loans than the rates we charge our corporate and commercial customers."

Retailers make the same argument. "The average balances of retail credit cards are much smaller than for bank loans, so our operating costs are a much larger portion of the finance charge than a bank's," said a spokeswoman at Sears, Roebuck & Co. "That's why department store credit-card rates do not fluctuate with prime rate changes," she said.

But H. Spencer Nilson, publisher and editor of a newsletter for credit-card executives, suggested another reason why credit-card companies are not lowering their credit. "Why would they reduce them when they will go back up anyway? . . . It would be very difficult for them to raise them."

A random survey of area financial institutions and stores reveals some of the credit terms currently being offered here: Mortgages

NS&T has dropped its rates for a fixed 30-year mortgage from 15 1/8 plus 1 point six months ago to 13 1/4 plus 1 point. One point is 1 percent of the face value of the mortgage. At United Virgina Bank, rates for the same mortgage have dropped to 12 1/2 percent plus 2 3/4 points from 14 3/4 percent plus 2 1/2 points six months ago.

Maryland National Bank's current 30-year fixed mortgage is 13 percent plus 3 points. American Security offers the same mortgage for 13 3/4 percent plus 2 points, while the National Bank of Washington offers it for 13 1/4 percent.

A relatively new type of loan that is being offered at some area banks is the "home equity loan," involving a line of credit secured by a second trust on the borrower's residence.

Such loans are offered at a cost of 14 percent plus 2 points at Citizens Bank and Trust Co. in Maryland and 13.99 percent and no points at First Virginia. United Virginia Bank offers this loan for 13 1/2 percent plus 2 points.

Riggs offers this type of loan at 1 1/2 percentage points over the highest prime rate published by The Wall Street Journal on the last day of each quarter. Home Improvement Loans

Home improvement loans range from 18 percent at Citizens Bank and Trust in Maryland to 14 1/2 percent at Burke & Herbert Bank & Trust Co. in Alexandria. The Bank of Virginia offers this loan for 17 percent, while the National Bank of Washington offers it for 15 1/2 percent.

United Virginia and Maryland National offer it for 15 percent. And American Security offers a 36-month home improvement loan for 14 percent. New Car Loans

New car loans in the Washington area range from the Maryland National rate of 13 3/4 percent for a 48-month loan to First Virginia Bank, which offers a rate as low as 12 1/2 percent for 48 months.

The National Bank of Washington's rate is 13 1/4 percent. American Security, NS&T and Riggs Bank charge 13 percent for the same car loan.

Citizens Bank in Maryland and United Virginia charge 13 1/2 percent, while Burke & Herbert Bank & Trust Co. in Alexandria offers the 48-month car loan for 12.99 percent.

"With automobile rates, people search around more than they do with personal loans, but automobile rates still move slower than mortgage rates," said Berson of Wharton Econometrics. Personal Loans

Because personal loans tend to be unsecured and, as a result, more risky for banks, they usually have higher rates. "Any time that a loan doesn't have collateral like a house or car, the lending rates will be higher because the bank doesn't have any security," Conner of American Security said.

Still, some area banks offer better personal credit rates than others.

While American Security, Riggs, Citizens and the National Bank of Washington offer personal 36-month loans for 18 percent, Maryland National offers the same loan for 17.9 percent.

Burke & Herbert Bank & Trust Co. offers personal loans for 17 1/2 percent, but they're for a maximum of 24 months, rather than 36. The Bank of Virginia offers this loan for 17 percent, and it automatically subtracts one-quarter percent from the rate if it can deduct monthly payments from a customer's checking account. First Virginia and Citizens Bank & Trust in Maryland offer personal loans for 15 percent. Credit Cards

The area rates for unpaid balances on bank credit cards such as Visa and MasterCard remain at 18 percent. Annual fees, however, may differ from bank to bank. The Maryland National Bank charges an $18 annual fee for both its Visa and MasterCard; First Virginia Bank, United Virginia and Bank of Virginia charge $15 annually.

Some retailers, including Raleigh Stores Corp. and Neiman-Marcus, also charge 18 percent interest on credit-card acounts for area customers. Others, such as Kay Jewelers, have different credit rates as a result of the varying state usury laws. Thus, Kay and Hechinger Co. charge Virginia and Maryland customers an annual 21 percent credit rate, but charge an 18 percent interest rate to D.C. residents, although D.C. law recently has been changed to permit interest rates as high as 21 percent. Several other retailers charge more than 18 percent. Sears imposes a 21 percent annual fee on its credit-card customers in the area -- saying it must charge higher rates than the banks for their credit cards because it doesn't impose an annual fee.

The finance charge for Woodies and Hechts' is 21.6 percent for all area customers. Officials for Garfinckel's declined to reveal its credit rates, saying it was company policy not to discuss them. A recent Garfinckel's bill, however, shows that the rate is 18 percent.

Shoppers buying big-ticket items, such as furniture and jewelry, may get better credit terms, especially during the Christmas season when some retailers have agreed to defer billing.

Hecht's, for instance, will not bill a customer for a $250 item bought before Christmas until February. At Woodies, any furniture purchase costing more than $300 and made before Dec. 25 will not be billed before February.

Both stores also offer special billing plans for customers buying a large amount of home items at one time. Although the interest rate is the same -- 21.6 percent -- as that for regular credit-card customers, these accounts give consumers more time to repay.

Sears has a similar program for consumers buying house siding, roofing, gutters or appliances. Purchases above $1,500 can be paid off over seven years at an 18 percent interest rate.

Other area furniture stores have credit plans allowing consumers to take two months to pay their bills without any interest charge. At the Colony House in Arlington, for example, if consumers pay one-third of their bill on deposit, another third 30 days after the furniture is delivered and the remaining third within 60 days after delivery, no interest charge is levied.