Getting a regular vehicle tune-up is a relatively minimal expense. Paying less than $100 can get you an oil change, multi-point inspection, and other minor maintenance work to keep your vehicle in good shape for several months or thousands of miles.

When it comes to more expensive repairs, however, many American drivers are unprepared for the repair costs. A recent AAA survey found that one-third of respondents, which the organization says is equivalent to about 64 million people in the United States, would not be able to pay for an unexpected vehicle repair bill without incurring personal debt.

AAA says the average bill for unexpected repairs is $500 to $600. This estimate includes average costs of $400 to $900 to replace a timing belt, $400 to $600 to replace an alternator or starter, and $500 to repair the brakes.

"The average cost of owning and operating a vehicle is more than $8,500 a year, and AAA has found that millions of Americans are failing to set aside a car care fund to pay for the upkeep of their vehicles," said John Nielsen, managing director of Automotive Engineering and Repair at AAA. "To avoid a surprise down the road, drivers should budget for monthly payments, insurance premiums, fuel costs, and the inevitable expenses of routine maintenance and repair."

The average annual vehicle cost figure is based on AAA's 2016 "Your Driving Costs" survey. This report determined that the typical driver spends $792 a year on maintenance and repair.

AAA suggests that drivers save at least $50 a month for unanticipated automotive expenses. The organization also urged drivers to keep up with scheduled maintenance, noting how repairs can be much more expensive if the vehicle is poorly maintained. A survey by AAA in 2015 found that 35 percent of respondents had skipped or delayed servicing which had been recommended by a mechanic or the manufacturer's maintenance schedule.

"Anticipating your vehicle's needs before problems strike is important," said Nielsen. "While it may seem that skipping maintenance and repairs can save money in the short term, staying on top of car care can save drivers hundreds of dollars in the long run."

AAA advised drivers to find a trustworthy auto repair shop for maintenance and repairs. In the event of an unanticipated vehicle repair, the organization said drivers should get a written estimate of the needed repairs and consider getting a second opinion from another shop. Drivers can also check to see if the business offers discounts, payment plans, or other options to minimize the expense or spread the costs over a longer time period.