Hello--Iv owned a number of volvos over the years and have used reg oil and changed at 3000 miles with no problems. I still use the reg oil in my 160k mi 1980 244GL,but, have switched my 945 turbo (99,000 mi) to mobil one a few oil changes ago after reading that it is beneficial to higher mileage cars as well. Just curious--would most agree with that changing to synthetic as I have will prolong turbo life. Since switching to mobil one-havent developed any leaks and overall --I would say that the eng actually runs a bit quieter now as before the switch--I sometimes had a little tapping sound just after start-up. Just curious as to whether or not I have done the right thing. I guess I should have asked this question before switching to mobil one--guess i got caught up in the advertised benefits--thanks for your opinions.

I switched to Mobil 1 on my 94 940 at 100K and at 110K it began to leak like a seive! Looks like the rear main seal! I'm thinking of switching back to clog up the leaky seals again.

Check out this website "Auto-rx.com." This is a natural product that clean the engine internals and restores the life of seals. It is not a solvent and does not affect the properties of the oil that you're using. A bottle is added with any good petroleum oil for 500 or more miles and then you can return to synthetic. Many people report great results with this product on the oil forum "bobistheoilguy.com." (The oil forum can be entered by going to the new message board. I haven't used Auto RX but now knowing about it I think that I should have used it to clean out engine internals before going to synthetic oil. I do not have any leaks though. But I have high solids levels on oil analysis. If I did have seal leaks I would give this stuff a try.

I highly recommend you go to both of these websites and spend some time reading all the information.

Good luck.
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92-944, 94-944, 97-960 - Amsoil lubes throughout,, K & N air filters, Silverstar headlights, Green Diamond Tires

I just ordered some through Auto-rx. I've got a 86 740 GLE, 147k miles, that was fine until I added Mobil 1 a couple of months ago. Now the seals in the front of the engine are leaking. Thought it might be a good time to try this product and see what it does before I change the seals. I also added Mobile 1 to my 94 945 so I might try the same treatment on that if the 86 results are good. Will post results.

Paul

I did the same thing you did a few changes ago and the insides of the engine look cleaner. I sprang a few leaks that were taken care of by tightening things up. I think I did the right thing.
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Bob Kraushaar '94 945T, '91 940T, '88 240, '94 F-150, '68 Shelby GT-500 KR

You did good, may want to think about Mobil 1 ATF synthetic for the transmision and power steering.
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1996 964 130,900 Miles

You made the right decision....all 4 of our vehicles run on Synthetic (Mobil1) since 1984. Hundreds of thousands of miles...........
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DEWFPO 1995 964 138,500 / 1998 S90 062,000

I switched my 940T to Mobil 1 at approx 75K. Now has 92K miles.
I once read that turbos on 940's last an average of 125K.
There was some sort of study where the lowest turbo life
on a 940 was around 60K and the highest at 230K. I recently
was offered to buy a 740T with 275K on the original turbo.
so I would think that if your turbo was in good shape
before the change over it would indeed prolong it's life.
If it was not in good shape, it probably isn't going to
help. But overall, Mobil 1 for many reasons is vastly
superior to mineral oil. HT

94 944T 92K
90 244DL 135K

I switched my three 240s over to Mobil 1 two years ago. What I like most about it is: the ability to maintain the film on the lubricated parts rather than having it drain down to the sump while the car sits overnight, and the ability to maintain low viscosity in cold weather during winter. We spend most of the winter at least in the 20s and dip into the singles from time to time. I appreciate the fact that the oil comes up to pressure almost instantaneously on those chilly mornings.

Rob Kuhlman