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High-Mileage Motor Oil and Oil Filters

Updated: Jun. 11, 2020

Get more life from your older car

FH11JUN_OILFIL_01-2Family Handyman
High-mileage oil and oil filters, which fight corrosion and other problems caused by combustion gases, can be especially useful in older cars. Here's how (and why) they work.

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High-mileage oil in older cars

Special filter juices up your oil

Install a high-mileage oil filter to boost the effectiveness of HM oil.

Old cars can actually benefit more from high-mileage oil than newer models. Combustion gases always leak past the piston rings and into the oil (even in new engines). The gases then condense to form corrosive acids. New engine oil contains enough acid neutralizers, anti-corrosion agents, detergents and foam inhibitors to counteract the effects of normal blow-by. But the extra blow-by in older engines causes the additives to wear out sooner. That’s where high-mileage (HM) oil comes in handy.

HM oils (about 75¢ more per quart) are formulated to handle the extra load and are well worth the money. To get even greater protection, add a high-mileage oil filter, too (the Fram HM is one choice; available through our affiliation with High-mileage filters contain a capsule of additive gel that dissolves slowly over a 3,000-mile period. So it continually feeds new additives into the oil. Together, HM oil and an HM filter add less than $7 to the cost of an oil change. It’s a good investment to keep your old wreck running longer.

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here’s a list.

  • High-mileage oil
  • High-mileage oil filter