850 Engine Oil

Volvo recommended 15W-40 for summer use in these engines in my manual and specifically says not to use 10W-40.

Chevron Delo 15W-40 is an excellent oil at a moderate price and is available in gallon jugs or quarts. Chevron Delo 10W-30 would be a good winter oil choice. Both are dual rated for both gasoline and diesel engine use and are some of the best conventional oils available.

If you want to spend the extra money on synthetics, Mobil-1 5W-40 "SUV" oil is an excellent choice year round.

Lots of oil discussion happens on the forums at:

John

My Volvo dealer (Fields Volvo, Libertyville, IL) uses Valvoline 10W30 in the summer and Valvoline 5W30 in the winter. Oil changes are recommended every 3000 miles.

We don't use dino oils, but instead use full synthetic. Fields charges extra for this, and use Valvoline Synpower 10W30 during the summer, and

5W30 in the winter, so that's what we use too. Recommended intervals are every 6000 miles.

My observations are that the flame-trap screen which we clean once a year has remained much cleaner after we switched to full synthetic a few years ago. There are claims that synthetic improves fuel efficiency, but I don't know if this is true.

Fields uses genuine Volvo oil filters. We use Mann filters from IPDUSA.

My 94 850 turbo is at around 198K now, and I use Castrol GTX 10W40 all year round (Atlanta), changing it when the service light comes on. Still running strong, doesn't burn a drop.

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My 94 850 turbo is at around 198K now, and I use Castrol GTX 10W40 all year round (Atlanta), changing it when the service light comes on. Still running strong, doesn't burn a drop.

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120k in a 93 850, used a good quality mineral oil, 15w-40 in summer, 10w-30 in winter, changed every 5000miles along with the filter. Was not burning a drop when we sold it at that mileage, with all the lifters totally silent from cold start and internals looking shiney and clean through the oil filler cap.

Now have a 60k mile old '97 S70 which is getting the same treatment.

Tim..

Thanks all. I am leaning towards the synthetic oil. I have had excellent luck with the conventional oil, but especially with the higher mileage '93, I want something that will hold up over the ravages of time and climate. Plus, with two kids now commuting to work and college, we are putting miles on more quickly and it seems that I am always getting on work clothes for the latest "change." The longer intervals with synthetic oil would be a welcome break.

Cheers

Woops, just had mine changed at a shop today and had them put in 10-40, since Im moving to the southern california desert next month, I guess I'll have to have it changed again for 15-40 instead, since it gets darn hot down there (109f today).

Does anyone know what synthetic oil is synthesized from? Is it just reassembled petroleum molecules, or does it come from a completely above-ground source?

To reply, please remove one letter from each side of "@" Spammers are VERMIN. Please kill them all.

Doug - Synthetic oil is bit of a misnomer. AFAIK all "fully synthetic oils" such as Mobil 1, are actually mixtures of base oils, which are directly refined from crude oil (no reassembling), to which "high performance fluids" are added. One high-performance fluid that all synthetic oils contain is polyalphaolefins -- you can consider these reassembled petroleum molecules. The identities of the other additives are proprietary to each manufacturer.

Ultimately most of it is from refined crude oil.

I found the article from Car & Driver that I read a few years ago. Turns out I had remembered most but not all the details correctly. Not all synthetics have polyalphaolefins. Here's the link to the article on the Car & Driver site:

'&article_id631&page_number=1

Bev,

I am truly impressed with the knowledgebase here. I have one more question. Is there a problem transitioning from standard oil to synthetic. From the sounds of all you have written, it appears that there would not be a shock to the system, e.g. oil seals, etc. Thanks again for all the great information.

Randy

Randy,

I think it would irresponsible for me to give you advice. I can tell you what I was told when I switched our cars. I was told to switch them gradually - first change 4 quarts dino, 2 quarts syn, second change

2 quarts dino, 4 quarts syn, third change full syn.

What I did was just switch to full synthetic right away and nothing happened. On brickboard there are some people with other Volvos (240s,

740s, 760s) who have said that it takes a while to condition the seals to synthetic.

Others would prefer to have an oil analysis done by a place like Blackstone Labs

to see if they shouldswitch to synthetic and then monitor the effects of the switch. Ihaven't done anything like that. The service engineers I know at Fields Volvo tell me that they don't hesitate recommending a switch to synthetic on any 850, S70 or V70, _regardless of mileage_ - I was very particular about asking that.

Beverly

My wife's "new" 850 also uses Mann filters. I am looking for a Hastings equivalent. Synthetic oils (so far) every 5000 km (3000 miles). What a vehicle! Compared to our '84 240 GL.

"Bev A. Kupf" wrote: ... snip...

Fields uses genuine Volvo oil filters. We use Mann filters from IPDUSA.

Get Royal Purple (about 6$ per quart) from Pepboys , but it is the best you can get, at least to what I have read on S40 Forums...

Switch to synthetic - it is well worth it, and is never too late. But before you decide on Castrol Syntec, read this article first:

'&article_id631&page_number=1 Castrol Syntec is not "synthetic" in the true sense of the word. I used Mobil 1 on my 760, and use Valvoline synthetic now (850/S70).

Mann work well too (are they Volvo OEM?)

'&article_id631&page_number=1>

Depends on whom you ask, apparently, since various authorities have decided that the "true sense" of "synthetic" apparently isn't related to "synthesis" (ie building up from smaller parts).

One comparative study of several oils, including these synthetics, is [1,2]. It suggests that Syntec is still better than most conventional (Group II base) oils, though not for high-temp / high-shear performance, where it did surprisingly poorly.

Another article [3] is more negative than the C&D one you cited regarding Group III oils like Syntec, versus their Group IV ("true" synthetics) competitors. It's discussing their performance in motorcycle engines, though I don't see that makes a tremendous difference.

The various sites I happened to look at all seem to rate Amsoil as the best product (and some claimed that Amsoil filters were also superior), for what that's worth.

Disclaimer: I'm not an organic chemist, automotive engineer, or amateur oil experimenter. I was just curious enough to do a bit of Internet searching - and I hope we all know how unreliable that can be.

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