Need a car loan? How does 6 or 8 years sound?

Americans today take nearly two years longer to pay off car loans than they did 30 years ago — a trend that has helped bury consumers in debt and automakers in deficits.

A typical car loan now lasts five years, and many stretch to seven, data from the Federal Reserve show. And the length will only go up.

Toyota in January announced it would offer seven-year terms on some loans. Analysts said eight-year offerings are rare but growing in popularity.

"Just a few years ago, some banks didn't even offer a 72-month [six-year] loan," said Jesse Toprak, chief economist with automotive research firm Edmunds.com. "It seems like a problem with no solution on the horizon."

For consumers, long-term loans tie up budgets, preventing people from saving or paying off other debts.

For automakers, the long loans can depress future auto sales because consumers are too strapped to buy new cars.

Don't blame today's economy.

The trend toward longer-term loans didn't start last year or even in the past decade. Since at least 1975, when the Fed began tracking auto-loan data, the length of car notes has steadily gone up.

The reason: Long loans mean lower monthly payments. That means people can buy more expensive vehicles and still be able to afford mortgages, credit-card bills and other expenses.

Jennifer Horton, an Akron, Ohio, mother with her second child due in July, said she will count on a long-term loan to help her buy a minivan later this year.

"It has to fit into our budget," Horton, 28, said while examining a Dodge minivan at the Cleveland Auto Show in February.

She knows it will tie up her budget longer to finance over five or six years, but the alternative is buying a car that may be too small for her growing family.

Many car shoppers had similar attitudes.

"The monthly payment is very important to me," said Michelle Legat, 32, of Broadview Heights, Ohio, while looking over a Chevrolet Malibu at the auto show.

She added that she would clearly choose a five-year loan for the Malibu over a three-year option for a smaller car.

"I don't like payments. I'm struggling right now between keeping my car that's paid for or taking on a payment. But it's time," Legat said.

"A permanent payment"

Consumers have spent more and more on cars almost every year since the Fed started keeping track.

The typical buyer in 1975 borrowed about $17,000 (in today's dollars, adjusted for inflation), to buy a new car. By 2006, that figure had climbed 63 percent, to more than $27,000.

But monthly payments haven't changed much.

In 1975, the average car buyer spent $523 per month (in today's dollars), compared with $496 now.

Jean Ann Fox, director of financial services for the Consumer Federation of America, said the fact that monthly payments have stayed within such a small range for so long is proof that consumers shop to fit payments.

"The car dealer hopes that [the monthly payment] is all you're looking at," Fox said. "That's a car dealer trick, to get people to tell them what monthly payment they can make."

Although consumers can generally afford the payments, the extended loan lengths destroy their ability to build wealth, she said.

"You end up with a permanent payment in your family budget. ... That's money you don't have for savings or anything else," she said.

Less interest being paid

Still, things could be a lot worse.

Despite the longer loans, people today pay less in interest — as a percentage of the total cost of buying the car — than buyers did a few decades ago.

While loans have grown longer, extremely low interest rates have made them cheaper.

In the early 1980s, for example, interest expenses made up about 25 percent of the cost of buying a car, even though buyers tended to pay off loans in less than four years.

In 2006, even as buyers paid for cars over five years, interest made up less than 12 percent of the cost.

Low rates also could explain why the auto industry has not had the credit problems seen within the home-mortgage industry. Some buyers default on loans, but the vast majority can still afford their payments.

Upside-down borrowers

The bigger concern for car makers is that the growing length of auto loans tends to depress new-car sales, Stoller said. If buyers choose not to buy new cars until the old payment is gone, an eight-year loan means eight years off the market.

But some people still choose to buy, even when they owe more on their loans than their vehicles are worth — what industry types call "upside down."

Upside-down borrowers don't make great car buyers.

If a buyer owes $20,000 on his car, but it's worth only $15,000 as a trade-in, he'll have to pay $5,000 at closing. Or, more often, he'll add $5,000 to the amount he's financing.

Toprak, Edmunds.com's economist, said upside-down sales are a big reason automakers have not been able to abandon cashback incentives on vehicles. Many buyers need the rebates to pay off their old loans.

In December, about 25 percent of buyers were upside-down on their trade-ins, Toprak said.