I was thinking of using synthetic oil. I live in a cold climate and would like to hear any opinions or experience regarding this. My car has 112,000KM or about 70,000 miles and I would like to keep it for many years.
Any high mile 850's out there using synthetic? Thanks.

Okay, I'll weigh in since I'm an Amsoil guy. For my money Amsoil, Mobil 1, and Chevron are the best you can buy. If you are a turbo, then go with the 10W-30, if not, you can go with the 5W-30. 10W-30 is beefier for turbo use.

Amsoil is extremely heat stable. I have used it in my Jeep Grand Cherokee for the last two years and approximatly 50K miles with only two changes and four filter changes. I never have to add a drop of oil between changes, and I get the oil analyzed at the end of its service to make sure everything is hunky doory -- always is.

Of course, the Jeep isn't a turbo. In a turbo application, I'd change it every 5K miles with an analysis with the change. From the analysis you can determine if you can safely extend your interval to 10K and beyond. Amsoil is specifically designed for extended drain intervals. The 3K drain interval is a myth with modern oils (even dino), and is only recommended to keep you comming back to Kragen, Autozone, et al. Also, Amsoil has a great program for regular customers, called the Preferred Customer Program. For $15 you can purchase all their products at wholesale prices. If you spend more than $100/year, the program will save you lots of dough. I think Amsoil is just trying to get their customers to become sales reps with this program, but the savings is worth the cost of admission anyway.

Regarding leaking seals. Amsoil is formulated to be compatable with all modern seals. Their oil also contains seal conditioners to prevent aged seals from leaking.

Good luck. I think you will be impressed with the switch, especially on cold starts.
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1999 S70 T5

Okay, I'll weigh in since I'm an Amsoil guy. For my money Amsoil, Mobil 1, and Chevron are the best you can buy. If you are a turbo, then go with the 10W-30, if not, you can go with the 5W-30. 10W-30 is beefier for turbo use.

Amsoil is extremely heat stable. I have used it in my Jeep Grand Cherokee for the last two years and approximatly 50K miles with only two changes and four filter changes. I never have to add a drop of oil between changes, and I get the oil analyzed at the end of its service to make sure everything is hunky doory -- always is.

Of course, the Jeep isn't a turbo. In a turbo application, I'd change it every 5K miles with an analysis with the change. From the analysis you can determine if you can safely extend your interval to 10K and beyond. Amsoil is specifically designed for extended drain intervals. The 3K drain interval is a myth with modern oils (even dino), and is only recommended to keep you comming back to Kragen, Autozone, et al. Also, Amsoil has a great program for regular customers, called the Preferred Customer Program. For $15 you can purchase all their products at wholesale prices. If you spend more than $100/year, the program will save you lots of dough. I think Amsoil is just trying to get their customers to become sales reps with this program, but the savings is worth the cost of admission anyway.

Regarding leaking seals. Amsoil is formulated to be compatable with all modern seals. Their oil also contains seal conditioners to prevent aged seals from leaking.

Good luck. I think you will be impressed with the switch, especially on cold starts.
--
1999 S70 T5

I've been using (and selling) synthetic for about 25 years now. I've changed over many cars with over 100,000 miles, and some with over 200,000. Go for it, as long as the engine isn't leaking or burning a lot of oil at this point.

I recommend using a good engine flush (such as AMSOIL or BG) before the change. If you don't, or won't, flush--change to synthetic. Watch for any signs of increase in oil consumption. If you get that, change the filter and top off. What happens is that the synthetic will clean the engine and carry gunk to the filter. If there is enough that the filter starts to fill up, dirty oil will circulate. Dirty oil doesn't seal as well as clean, and this can lead to increased consumption. Also, if the oil seems pretty dirty, you might drain the first batch after 3-4,000 miles (especially if you don't flush first).

If you have a turbo you are foolish to use anything but synthetics. In a non-turbo car I would have to say that with 3,000 mile changes you will probably be fine using dino oil for a very long time. For my money, I would go with the synthetics.

If you have a turbo change every 5,000 miles or 6 months. If you have a non-turbo I would go no more than 10,000 miles or 1 year, and change the filter at 5,000 miles.

I use Mobil 1 5W-30 in all my cars. In my opinion Mobil 1 and Amsoil are way better than the rest of the synthetics, which in turn are way better than dino oil. Don't bother with the synth-blends, spend a couple extra bucks and go for the synthetics.

ALSO, for the best filters either buy either Amsoil or Mobil 1 oil filters. If you don't want to spend $12 on a filter then buy the stock filter from the dealer or MANN filters from IPD or some other source. Stay away from Fram or any of the other mass market filters.

My $.02: ALL seals are subject to (not necessarily PRONE) to leaking, based on age, driving habits, type(s) of oil used, frequency of oil/filter changes, etc., etc. Because dino can ;coke' (burn and harden), it can 'sludge up' against a weak seal, and keep that seal from leaking (in theory). Then a new owner or new mindset comes along, tries synth (and they are NOT all the same, as you no doubt will read more about as this thread lengthens) only to find leaking. Yes, the synth has started to clean up (hopefully there was a short-interval flush, as a transition to the all-synth-forevermore regime) and/or clean out the residue(s) from the dino oil. One of the KEYS to keeping your engine happy is to make sure that the PCV system, and all its connectors, nipples, etc., are clean-and-clear (AND the flame trap in the PCV, if the car is NOT a turbo). Will synth 'eat' seals? Nobody seems to think so. Will it p-o-s-s-i-b-l-y contribute to leaks after a switchover? Possibly, maybe even probably. 70,000 miles is not a lot for a well-maintained Volvo, but it IS a lot of miles for a neglected car, of ANY marque. (E.G., I have 215.000 miles on 'Brunhilde:' she's just a teenager, in my book!)Food for thought. No doubt some of the Amsoil dudes/dudettes will weigh in, as well. YOU decide! --PD. (I use Mobil 1, no leaking seals....touch wood!)

I live in a cold climate too. I have always used dino oil, but this year I am using syth. (I am at 90K miles). I did some research, and it seems synth may be more protective in colder starts (flows faster), and you can get nice weights with it. The only thing I can tell you is that I have heard many times not to use Mobil1 in engines with "higher" mileage because there are additives in it which can weaken and damage old seal and gaskets-thereby causing leaking. I have a friend that can attest to this through his experience. He said he runs Mobil1 in newer vehicles and castrol syntec in older ones. Both oils are comparable in quality, just the additives issue.

By the way, I got 240K out of a volkswagon using dino oil, and the engine didn't burn or leak anything...I think volvo engines are as good, if not better quality, and syth isn't really necessary...but I thought I would try it out.

db

What is considered "higher mileage" on a Volvo? My husband and I just bought our first (a 1995 850Turbo Wagon) and the previous owner told us he always used Mobil 1 - it's more expensive but a good oil, etc etc. The car has 79,000 miles on it. Now it's developed a bit of an oil leak and I don't wonder after reading your posting if that's the problem. Anyway, I didn't know what Volvo owners considered "high" mileage? Thanks.

Well, if anyone's curious to how our saga concluded - it turned out to be a rear main seal, not at all related to the oil (kudos to you all) We got it fixed and a few hundred bucks later, I've got an oil-leak free car that is a blast to drive. My husband's still having a hard time getting used to the noisiness of it, but I told him just to turn up the radio :}

I'd say that high mileage in your case could be 300,000, since the car was run on synthetic up until now. Engine wear is reduced to almost nothing with a good synthetic. Mobil 1 certainly isn't causing leaks at this point.

You're probably barking up the wrong tree. In the 70s the detergant effects of synthetics would sometimes expose pre-existing oil leaks that were sludge filled when an engine was switched over. (there were also some issues with the seals which Mobil 1 was rumored to shrink)

but, by the 90s, the seals are definitely not impacted by the modern synthetics.

you probably have a leaking o-ring on the oil return line) see bay13 on www.volvospeed.com for details.

it's not the oil causing it's own leak.

I use Mobil 1 5W20 in the winter (98 S70). A must for cold climates. Flows instantly compared to non synthetic. I guess high mileage to me could start at 125,000 miles and range to 250,000 miles.