Beyond the odometer: What matters most in a used car

Used car shoppers love round numbers: the model year and the mileage on the odometer.

The conventional wisdom is that newer is better and lower mileage is best. A 4-year-old car with 50,000 miles must beat a 9-year-old car with 100,000 miles, right?

Not necessarily. Although age and mileage are part of the story, they are not the only characters.

The most important factor in predicting a used car’s reliability is its maintenance history. A well-maintained, high-mileage older car can easily be a better value and a more dependable vehicle than a neglected, low-mileage younger one.

The power of paperwork

Think of a car’s service records as its medical chart. A thick folder of receipts for routine oil changes, tire rotations, fluid flushes and other scheduled services is a strong indicator of a healthy vehicle. This paperwork proves the previous owner was diligent and invested in the car’s longevity. It allows you to verify that critical services, like timing belt replacements or transmission fluid changes, were performed on schedule.

Conversely, a car with few or no records is a gamble. Gaps in service or repeated repairs for the same issue are significant red flags. Without documentation, you are buying blind, trusting only the car’s appearance. A clean exterior and tidy interior don’t mean much if the previous owner starved the engine of fresh oil.

Decoding the miles and years

Not all miles are created equal. A car that has accumulated 100,000 miles primarily through gentle highway cruising has endured far less stress than one with 50,000 miles of stop-and-go city driving. City miles are harder on the brakes, transmission and suspension.

According to the latest figures from the Federal Highway Administration, drivers in the United States travel an average of about 12,200 miles per year. However, knowing how they drove those miles is more telling than the total.

Be cautious of unusually low mileage on an older car. A vehicle that sits for long periods can develop its own set of problems, including dried-out rubber seals and hoses, cracked tires and corroded brake components. Old, degraded fluids can damage the systems they are meant to protect

A Hummer H2 for sale at an independent dealership in Chattanooga, Tennessee, on Nov. 11, 2023. Photo courtesy of Chris Hardesty.

Age also brings trade-offs beyond mechanical wear. According to a May 2025 S&P Global study, the average vehicle on U.S. roads is now 12.8 years old. Although a well-cared-for car from a decade ago can be mechanically sound, it will be technologically dated, and this is most apparent in its safety features.

For many shoppers, the absence of the latest convenience and safety tech is the most significant compromise. An older car will typically have foundational safety equipment, such as air bags and anti-lock brakes. Still, it may lack the advanced driver-assistance systems that are now common. These features are proven to reduce crashes. Forward collision warning with automatic emergency braking can actively brake to prevent or lessen the impact of a rear-end collision. Blind-spot monitoring provides critical alerts for lane changes, while a rear cross-traffic alert acts as a second set of eyes in parking lots, helping avoid fender-benders.

Active safety systems are a primary reason newer cars often provide a measurably higher level of protection. Opting for an older car means consciously forgoing these modern safeguards. You will also miss conveniences like Apple CarPlay and Android Auto. For some buyers, the substantial cost savings are worth this trade-off. However, you must weigh your budget against the tangible safety benefits that a more modern vehicle provides.

Finalizing your decision

Some brands, such as Toyota and Honda, have strong reputations for long-term reliability, but a vehicle’s individual history is often more important than its badge. No matter the make or model, a few final steps are crucial before you buy.

First, if you are not paying with cash, secure your financing before falling in love with an older used car. Many banks and credit unions have restrictions on the age and mileage of vehicles they will finance. For example, a car with more than 125,000 miles or one that is older than 10-15 model years may be ineligible for a loan from some institutions.

Second, and most importantly, always invest in a prepurchase inspection from a qualified, independent mechanic. For a relatively small fee, a professional can put the car on a lift and identify potential issues that you would never see, from hidden rust to early signs of a transmission problem. This inspection, combined with a thorough review of the vehicle’s service history, provides the clearest possible picture of the car you are about to buy. These steps empower you to look past the odometer and make a truly smart investment.