More people in this economy are falling behind on their car payments. That’s especially true for the riskiest borrowers. Last month, 6.65% of subprime borrowers were at least 60 days late on their payments. 

That is the highest delinquency rate on record, dating back to the early 1990s, according to Fitch Ratings. This comes just a couple months after Tricolor Holdings, a subprime auto lender, abruptly declared bankruptcy.

A car can be an economic lifeline, said Jessica Caldwell, head of insights at car buying site Edmunds.

“Going to school, going to work, taking their kids where they need to go. It is really, kind of, the cornerstone of your life for most Americans, especially in places that don't have good public transportation systems,” Caldwell said.

And unlike many mortgages or student loans, which have more borrower protections, she said the consequences of missing car payments can happen fast.

“Their car could be repossessed,” Caldwell said.

And the reason subprime delinquencies are rising now should be clear to anyone who’s gone car shopping lately.

“Car prices are at record highs,” said Ted Rossman, senior analyst at Bankrate. “We're talking about roughly $50,000 on average for a new car.”

Combine that with higher interest rates in recent years and it means the cost of financing a car is rising even faster than the cost of everything else.

“​​ When we look across all different loan products, the average loan size amongst auto loans has increased more than any other loan product,” said Rikard Bandebo, chief strategy officer and chief economist at VantageScore.

For Christopher Palmer, a finance professor at MIT, the delinquencies suggest a growing strain.

“The vulnerable part of the economy is having an even tougher time making ends meet,” he said.

But if issues with subprime lending call to mind the subprime mortgage crisis, Palmer said not so fast.

“There is a substantive difference between subprime car loans and subprime mortgages in that the mortgages tended to be systemic,” he said.

Mortgage balances economy-wide are nearly eight times greater than auto loans, according to the New York Federal Reserve.

“And so, you had a lot of financial institutions that could not withstand the foreclosure crisis in houses,” said Palmer. “We don't see a lot of institutions right now that seem so tied up and so exposed to car loans.”

Plus, Moody’s Analytics senior economist Mike Brisson said even though more people are behind on car payments, “we’re not seeing them go into bankruptcy and defaults.”

Which means, banks aren’t writing off these loans just yet.