[Richard D]

Hello all, My 90 coupe now has 141,500 miles on the clock and I change the oil about every 3,500-4,000 miles. It can take five months to get that much mileage, car is driven every day. The dip stick shows no difference at 4,000 miles, no leaks or tranny leaks. I have been using Pennzoil W10-30 here where it is always above 60 degrees and Pur-One filters. Should I switch to the new High mileage oil now available? For you engineering types is it a different oil or marketing hype? I keep thinking, if it's not broke don't fix it, but if it is a better oil for high mileage engines..... catch-22 HELP!
Many Thank's
Richard.

[kennyw]

decide for yourself.......

Guys:> after viewing this link you will find you know less about motor oil then ever.......ken

All About Motor Oil. link is on this thread:> Dino Oil vs Synthetic (Multi-page thread 1 2).......page #3

[padgett]

Dunno but for a buck a gallon extra am willing to try.

[CHAS1]

Why look for trouble?
You have no leaks!
You are using a good oil and filter.
I would just continue what you have been doing.
My 2 cents

[JZRIV]

High mileage oil is too general of a term for me and all cars with higher mileage can't be painted with the same brush.

Consider the difference in internal engine wear with a 140,000 mile car that has had regular oil changes at or before the recommended interval, a higher percentage of highway miles vs city driving, as well as not being driven in extreme cold or hot climates compared to another 140k engine that has had oil changes exceeding the recommeded intervals, a higher percentage of city driving or short trips vs highway miles, and all in a hot or cold climate.

I think you have to evaluate each car and how it was driven when deciding whether or not to change to a HM oil. Common sense tells us one oil would not perform equally in an engine with considerable wear vs an engine with factory new clearances. There is some merit to using an oil formulated for an engine with assumed higher clearances due to high mileage. So at some point when clearances reach a certain level from wear (extensive testing would need done to determine this) a HM oil would provide better protection. Then the question becomes would it be so much better that you would keep the car long enough to realize any perceived benefit?

Considering the condition of your engine, I would not change the type of oil.

[Richard D]

Thank You to all who took the time to answer my question. I am not worried about the extra cost, it seems that tolerances are still tight and within spec. I am going to send a sample of 4K old oil out for anlaysis. That should tell me if there is any bearing wear or any reason to use the high mileage oil. In the meantime I will keep the same oil/filter regiment.

[sfair]

One thing that high milage oil includes is an extra dallop of seal sweller. If you have no leaks, why give your seals a punch in the nose (which results in swelling) if they do not need it?

[Telco]

I would add to this that unless you started using synth oil early on, it's not a good idea to switch to it. Synth oil will clean out any deposits left inside the engine by the dyno oil, which can cause you to develop leaks. This is even though you have been keeping the oil changed, it's just the nature of the beast. I don't like seeing anyone switch from dyno to synth past 75K miles, and really don't suggest it once you hit 6 digits. Usually the time to go from dino to synth is around 10K miles, as rings seat better with dino. It's not guaranteed that the leak problem will develop if you switch to a synth at this time, but this is the norm.

I'd just keep running what you've been running, it's obviously doing the job well.

[kennyw]

If anyone took the time to read my oil link they would find DINO oil can now be refined so well it can be called synthetic. MOBIL lost a court case on that one. You will find that you know very little about oils of any kind. It is an eye opener...........ken

[Mike_s]

Is this the link you were referring to KennyW

All About Motor Oil

Here's another one some might find interesting from the Antique and Classic Car Club of Canada

http://www.acccc.net/index.php?optio...ance&Itemid=37