Maintenance items by age vs mileage

[pete6032]

When it comes to vehicle maintenance, which items should be considered by age versus mileage for vehicles that aren't driven a lot? For example I know brake fluid should be changed every 36 months because it can absorb moisture and performance is degraded with time. Tires, even if you don't drive much they can start to dry rot and should be changed after 5-ish years. Spark plugs I would see strictly as a mileage change since the plugs don't really lose performance sitting unused. What about things like fuel filter, other fluids like oil, transmission, etc?

 

[dave_the_nerd]

Most fluids are age/mileage (X months or YYYY miles, whichever comes first.) The specifics will be listed in the maintenance schedule of the car, different grades or types of fluid can last more/less time.

Rubber bits also tend to be age-related. Besides tires, motor mounts, bushings, etc., all can rot, dry out, or crack with age. (And the age limit on tires is more like ten years, to be fair.)

 

[BonzaiDuck]

Most fluids are age/mileage (X months or YYYY miles, whichever comes first.) The specifics will be listed in the maintenance schedule of the car, different grades or types of fluid can last more/less time.

Rubber bits also tend to be age-related. Besides tires, motor mounts, bushings, etc., all can rot, dry out, or crack with age. (And the age limit on tires is more like ten years, to be fair.)

Here's an interesting example.

On my (totally restored) Isuzu Trooper 95, my records show that I replaced the starter and solenoid in 2003. That was 82,000 miles ago, and you would think that a starter would "last" 82,000 miles and not likely to go bad so soon.

But think about it. If the vehicle has mostly served for errands, grocery runs and other short local trips, you've made the starter work frequently over the 20 years. Not as if you took the car on vacation traveling several hundred miles between fuel stops on a regular basis. So it might well be the case that 82,000 miles would see the starter die under that sort of usage profile.

On the rubber parts including tires, exposure to ozone in the air will deteriorate those items. So even with plenty of tread left, you should replace the tires about once every five or six years.

I replace my oil every 2,000 miles, even though synthetic is supposed to last 10,000. Coolant? Just check it from time to time and use additives that prevent corrosion.