More than half of Americans (56%) now say their monthly lease and car payments are enough of a burden to prevent them from making other big ticket purchases, according to a survey.

The Cambridge Consumer Credit Index found that 17% of those surveyed making car loan payments said these loans are a major burden, up from 11% who felt so in 2003. 39% now say the loans are a minor burden, down from 44% a year ago.

One reason that the level of burden has increased on many consumers is that average car payments have risen because of higher car prices. 17% of those with car payments are spending between $US500 and $700 a month, up from 10% who paid that amount in 2003. 43% (down from 50% a year ago) are paying between $300 and $500 a month, while 32% (unchanged from a year ago) are paying less than $300 a month.

The level of pent-up demand for new vehicle purchases in the next six months remains similar to a year ago, with 8% of Americans very likely to buy a car (up from 6% in 2003) and 8% somewhat likely to purchase a new vehicle (down from 11% a year ago).

"The results of the [survey's] wildcard question show that car loans and leases are becoming a greater burden on Americans' budgets, since the price of cars has been rising, resulting in larger monthly car payments for many," said Consumer Credit Index spokesperson/financial analyst Jordan Goodman.

"These larger payments are becoming an increasing burden on consumers, restraining them from purchasing other large ticket items that they would like to buy."