Miles are typically best for other factors such as chassis, suspension, and driveline components,” he noted. ... While miles may be best for measuring many fleet analytics, hours is an important component to ensure total visibility into all aspects of fleet maintenance and measurements.

Do car chassis wear out?

It depends on how much wear and tear the chassis has, and if it's corroded, been previously damaged, etc. For a car that is properly maintained, has no corrosion, and been in no accidents, the chassis probably isn't weaker.

Does it matter how many miles are on the body of a car?

A car's life isn't determined by miles driven.

Mileage is just one indicator of a vehicle condition. Theoretically, a vehicle that has covered more miles has more wear and tear, but a car with 60,000 miles on the odometer can easily be in worse shape than one with 120,000 miles.