What is High Mileage Oil?
High mileage oil is pretty much what it sounds like, oil for engines with a lot of miles on the odometer—more than 75,000 miles to be exact.
Surely you've seen an older car with a worn out interior—broken handles, cracked trim... well engines are no different. The combustion of gasoline wears down the engine over time. While motor oil can help slow the wear, it cannot prevent wear. Even if you change your oil on time (and you should), engine parts like the crankshaft, pistons, rod bearings, and valve seals will not be in as good as condition at 80,000 miles as they were at 15,000. That's why high mileage oil contains special additives to better prevent the sort of problems that typically arise in high mileage engines compared to conventional oils.
3 Ways High Mileage Oil Protects Engines Better Than Conventional
1. Prevent Leaks with Seal Conditioners
Seal conditioners recondition seals that shrink and become brittle due to natural aging. High mileage oils also contain seal sweller and conditioners to help reduce leaks, eliminate smoking and improve engine performance.
2. Clean Engines with Extra Detergents
Detergents help keep older engines running clean. Engines with high mileage create sludge faster than newer engines. High mileage oils contain anti-oxidant additives to fight sludge and help prevent viscosity breakdown.
3. Fight Friction with Extra Anti-Wear Agents
Anti-wear agents help prevent future wear. High mileage engines wear at a faster rate than newer engines. High mileage oils contain additives that help prevent metal-to-metal contact and reduce future wear.
When to Use High Mileage Oil
Start using high mileage oil after you have 75-100,000 miles on the odometer. These could also be signs that it’s time:
- Increased oil consumption
- Engine is slow to start in cold or runs hot on warmer days
- Decrease in throttle response
- Decrease in gas mileage
- Minor leaks
Get The Brands You Trust
AutoZone has a wide selection of high mileage motor oils in your favorite brands, plus all the parts, products and advice to help you do the job right. Visit an auto parts store near you today or browse our full selection of motor oils online.