High Mileage Oil Can Help Extend Engine Life
Motor oil is arguably the most important non-mechanical component of any vehicle’s engine. It lubricates and cools hundreds of close-tolerance moving parts to minimize friction and wear. It seals piston-ring gaps and cylinder-wall valleys to keep contamination to a minimum. It protects the engine from collecting lubrication-crippling sludge. And it prevents corrosion from moisture and/or acids that may find their way into the engine.
But just as our bodies require extra care as we age, our cars, trucks, and SUVs can benefit from a specific class of motor oil formulated to help engines keep turning after they have racked up 75,000 or more miles.
What Is High Mileage Motor Oil?
High mileage motor oil is designed specifically for older cars with high mileage (75,000 miles or more). Compared to regular motor oil, high mileage oil contains special additives that improve engine longevity.
What Is Considered High Mileage?
When oil manufacturers refer to “high mileage cars,” they are usually referring to cars with 75,000 miles or more on the odometer.
High Mileage Oil vs. Regular Oil
High mileage oil contains special antioxidants, detergents, and additives that can help reduce engine wear and minimize the chances of sludge buildup. Importantly, high mileage oil helps prevent aging seals and gaskets from becoming brittle and causing leaks, which are usually evidenced by oil stains on the pavement where the car is parked. This can lead to increased oil consumption and even costly engine damage.
High Mileage Oil vs. Synthetic Oil
High mileage oils are usually synthetic oils. They are typically based on either full-synthetic oil or a blend of synthetic and conventional oil. Synthetic oil offers greater protection in extremely high temperatures, and its ability to flow without difficulty in cold weather helps make engine starts easier in freezing weather. (Synthetic oil is otherwise recommended for speedy sports cars and vehicles used for heavy-duty towing and hauling.) Whether full or partially synthetic, high mileage oil is more expensive than standard grade oil.
High mileage synthetic or synthetic blend oil, as with the conventional variety, is available in various weights that are labeled according to their viscosity, a measurement of an oil’s thickness or resistance to flow. This is expressed as a series of numbers, such as 10W-30. The lower the first digit, the more resistant the lubricant will be to thickening in low ambient temperatures (the “W” stands for winter). A higher second number means it provides added protection against thinning when the weather turns hot. Check the owner’s manual to see what’s recommended for your vehicle based on how and when it’s driven.
So, Is High Mileage Oil Worth the Money?
Though it provides an added layer of protection for older cars, some sources suggest a specific high mileage blend might not be worth the extra money if a car’s engine is not already leaking or is burning oil excessively. If that’s the case, choosing a higher viscosity (thicker) grade conventional oil and/or using stop-leak additives to bolster seals can be a lower-cost alternative.
Check an Older Car’s Oil Once a Month
To further help extend the life of an older car, truck, or SUV’s engine, drivers should check the oil level at least once a month between changes, since extended driving with a low oil level could lead to engine damage.
If your car needs more oil, follow the instructions provided in the owner’s manual. Add a quart of oil when the level indicated by your engine’s dipstick reaches or drops below the “ADD” marking.
Can You Mix High Mileage Oil and Regular Oil?
Despite what some drivers may believe, if the need arises, you can mix high mileage motor oil with the conventional or synthetic variety (or vice versa) in your car’s crankcase, though you’ll lose some of the benefits of the high mileage oil in the process. You can also switch back and forth from one type to another at subsequent oil changes without fear of engine damage.
How Often Do You Change High Mileage Oil?
As with any type of motor oil, always follow the automaker’s recommendations on oil-change frequency outlined in the owner’s manual. There are usually intervals given for normal and “severe” use. “Severe use” can include frequent short trips, towing or hauling, stop-and-go driving, or operating in extremely dirty/dusty conditions. Severe use requires shorter change intervals (say 3,500 vs. 7,500 miles).
Next Steps
- Find a Top-Rated Mechanic
- Track Your Car’s Maintenance Easily With the Carfax Car Care App
- Find a Used Car With a Free Carfax Report
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