High mileage oils


What is the opinion on high mileage oils. Are they necessary and if so, at what mileage should they be used?


High mileage oils are usually synthetic and can last up to 7k miles (or more) before a change.

However, personally, I would change the filter at the halfway point.
That’s just me though.

These oils are use from the assembly line on.

For the most part, stick with what the owners manual recommends.


So its not gonna benefit me to use these oils at 207,000 miles on a car? No increase in power, mileage, etc…


There are three kinds of “high mileage” oils.

  1. For cars with lots of miles. This is a bad description, but the one they use. It really should read "For cars with oil leaks and worn engines. They may help buy a few more months or even years for those cars.

  2. Oils that claim to give higher miles per gallon. Don’t bother, use a good synthetic oil of the weight specified by the manufacturer for the conditions you are driving in.

  3. Oils that you can leave in the car for more than the recommended miles. Don’t, just do oil changes as specified in the manual.


Any recommendation for the “oil leaks and worn engine oils”…as far as a brand. I run a 5-30 in it now and the van is not run hard or in many dusty conditions. Mostly just family running…


there is absolutely no need to switch over to any high mileage oil unless you are having either a oil burning problem or an oil seal leak problem. You can probalby go well over 100,000 miles before any, if ever, these things happen. Do not change anyhing that is working well (like the oil you use or the interval of change you are comfortable with) unless you start to encounter a problem. they contain additives and conditioners you do not need until a prioblem develops, if ever.

If it ain’t broken don’t fix it!!!


Why don’t you tell us a little more about your car?

  1. Does it leak oil?
  2. Does it burn oil?
  3. What oil have you been using and how often have you been changing it?

Most “High Mileage” oils will hurt your mileage (slightly) and decrease your power (very slightly).


Car has 207,000 miles on it. Does leak a “little” oil. May burn a little as well. I try to keep it on a schedule every 3K to 5K miles. Propably need to do it a little more now that it has this many miles…


I’ve read that high mileage oil tends to be thicker so that it remains in the larger gaps better than thin oil. Larger gaps are usually found in high mileage engines, but not always.


If your engine is tired and burning some oil, simply try a thicker weight. If not, then you don’t large enough spaces between the wear surfaces to be trying to push a heavier lubricant through and you should stay with the owner’s manual recommendations.

www.carbibles.com has a good primer on oils.


You may want to try a high mileage oil like Valvoline Maxlife.

It has extra seal conditioners to help reduce or eliminate your oil leakage.

It is also slightly thicker which also help reduce leakage.

It has additives that reduce the amount of oil you burn.

It also has some extra anti wear additives.

Most “high mileage” oil have these same characteristics.

Maxlife is a synthetic blend that you can be comfortable changing at 5k mile intervals (unless you are leaking coolant or excessive fuel into your oil).

I now use Maxlife in my Windstar 3.8L (137000 miles) as a preventative measure because this engine has a history of seal and gasket problems.


It isn;t really that it remains in the gaps better. The way the system works is that oil is forced by the pump in between the wear surfaces under pressure. That pressurized oil is what keeps the parts seperate under load. When the spaces become too large, the oil runs through too easily and the pressure can’t be maintained, thus that pressurized fluid barrier is lost. Sort of like trying to blow up a balloon with a hole in it, you won’t get the pressure up. Thicker oil can’t get pushed through as easily and allows the pressurized barrier to be maintained.

While, I gues that can, after all, be described as staying in the gaps better! I concede!


Let’s assume that you have a high mileage car and you are dripping oil. I’d try one of those high mileage oils . . . they are supposed to soften up old seals and gaskets and help to stop the drips. If you are burning oil, try a heavier weight, as suggested by the others. If you are experiencing no problems, just keep doing what you have done for the first 207,000 miles. No oil is magic, most (expensive racing oils claim otherwise) won’t increase power or horsepower. If you want better mpg, try a lighter weight. But the best advice if you have no problems is to use whatever the manufacturer recommends and change it often, like every 3-5k. Rocketman