Extended performance engine oils use in high mileage cars

There are new engine oils that can go as far as 20,000 miles. Does it worth using these oils in engines with high mileages?

Recent advancements in oil technology has birthed extended performance oils.

We can use them in our cars for as much as 15,000 miles to 20,000 miles before oil change.

Different manufacturers have come up with their extended performance engine oils.

Examples are Mobil 1 extended performance engine oil and Castrol Edge extended performance. Both companies claim that their oils can go up to 20,000 miles.


These are engine oils that have good viscometric and antiwear properties. They also have other good properties like resistance to oxidation under conditions of high temperature, high load and high speed. These engine oils are usually synthetic oils which is preferred but the advantages of extended performance technology is that it may be extended to oils containing base stocks of mineral origin.

These oils have good viscosity temperature relationship. They also have good resistance to oxidation under high temperatures, have resistance to hydrolysis in the presence of the water produced as a combustion product.

Back to our initial question of using these oils in older generation cars.
Extended performance oils are actually made for modern engines of which most conform to low emission standards. Due to this, in addition to the advantages of this technology, the oil is able to stay clean for a longer time in the engine.

Now, older engines are poorer in emissions and will contaminate the oil quicker. As a result, even though the extended performance oil is rated to last to up to 15,000 miles to 20,000 miles oil change interval, I do not recommend that the oil should last that much in older cars because of quicker contamination. Anything between 8,000 miles to 12,000 miles would be okay, depending on some factors like the condition of the car's engine, the oil change interval recommendation on the oil container or datasheet and the oil change interval recommended by the manufacturer of the car.

From the above, we can deduce that using these extended performance oils in older engines will not be pocket friendly at all unless we want to push the oils to the mileage written on the oil containers. This might hurt sooner or later.

Secondly, oil filters for older cars are not extended performance filters, many are meant to be replaced at most 5,000 miles except the car model now has extended performance version of the oil filter.
If the normal filter of the older model car is to be used, it needs to be replaced 3 to 4 times between oil changes when extended performance oil is used. This might add extra cost due to the fact that a single extended performance oil filter will likely be cheaper than four normal oil filters, not to talk of labor costs during those oil filter changes.

In summary, for older cars, if we are considering engine protection and value for money, we can stick with normal synthetic oils.