What is the general consensus on using synthetic oil in an old 200-series oil-cooled turbo? Mobil 1 seems to be "the stuff" around here, but I can't see throwing away that kind of money every 3000mi. The owner's manual recommends changing the earl 'n filter every 3500mi for the turbo engine (b21ft). Is it OK to change at 5000mi intervals or greater if you run a syn oil? Does Mobil 1 come in 20w50? All I've seen on the shelves at the local Checker's are 10-30 and 10-40 weights. Doesn't ever get cold enough here in No. California that I would need that kind of protection.

Also, why does there seem to be this general bias on the BB against Fram, Pennzoil, etc. filters? I've been told to use Mann filters if I'm really serious about maintenance, but these damn things are smaller than the original Volvo OEM filter, and smaller still than the equiv. Fram part I can get at Checker's. How can the filtering area possibly be 10% greater as IPD claims??

Robbie, go buy some of those cheapie oil filters, and buy a mann filter; then cut them all open to see how they're built. Then, if you are still unable to understand why the mann filter is the best choice, go ahead and be a cheapskate. I use mobil 1 15w-50 in my turbowagon, year-round, WHY????? because it can take the heat that the turbo can dish out and not break down like regular dino lubes. Mobil 1 and a Mann filter every 2,000 to 3,000 miles is a hell of a lot cheaper than replacing the turbo or engine. Plus, I don't have to worry if it can handle the load when I am running at a GVW of 6,000 lbs at 70 mph and then decide to fly by some jerk hogging the fast lane. I suggest that you make a hard run at night, pull over and raise the hood; then look at the exhaust manifold/turbo: it will be glowing RED. And I would hope that you would have enough respect for your motor to let it idle until there is no more glow before you shut down. It takes 7 minutes for mine to quit glowing before I shut down.

A Volvo turbo motor is either 130 or 140 cubic inches in displacement; yet it can put out 130 to 162 horsepower, stock. You are probably not old enough to remember when one horse per cubic inch was considered a goal to be pursued by many and achieved by few. The point of this history lesson is that your turbo motor IS a high output motor; and if you are going to complain about how expensive good oil and filters are, you are not worthy of that car.

I have asked this several times and get varying responses - what effect might synth have on old oil seals? My 86 740 has some very minor oil leaks and I am concerned about making them worse. But all the other stuff I read about synth makes me want to go with it.

Well, synthetic is great stuff, but it is not a mechanic in a can, or a cure-all. It doesn't replace missing metal, doesn't fix worn gaskets or seals, doesn't keep headlights from going bad.

If you already have a leaky seal, synthetic will either:

go through at a faster pace, OR

clean and soften the seal, so that it reseals.

has a display with three filters cut in half. One is a Fram, another is (I believe) Purolator and then the Volvo filter. The Volvo filter is better constucted, uses heavy springs an da metal cage around the filter. The other filters are cheaply made with lighter springs and just cardboard filters. If you saw it you would never use any other filter again on your car. The next time I go I will take a picture and post it. There really is a HUGE difference in quality. Yes it is a matter of preference and how much you want to spend. I would say if you do a lot of stop and go then a Synthetic oil is better. If you do a lot of highway driving where your speed is constant then a dino would suffice. I prefer Synthetic oil for its break down values. It will end up costing me less in the long run if I use a higher quality oil. I want my engine to last.

1) With a turbo of any age it makes sense to use synthetic for several reasons, but the major reason is the huge difference is high temp. oxidation, evaporation and what I call "solidification/carbonization" (when the viscosity enhancers and pour point depression agents in dino oils have boiled off or broke down). The oil crud that ruins your turbo just doesn't happen with synthetic oil...even under pretty severe conditions.

2) With Amsoil 10W-30 I go 10,000 miles between changes with great results (car has 213,000 miles) and when I get the oil analyzed (even though I change at 10K) it is still fine.

3) Mann makes the Volvo filter and they are the same size.

Paul Seminara wrote:

> The oil crud that ruins your turbo just doesn't

> happen with synthetic oil...even under pretty severe conditions.

Paul,

What about the crud that plugs up my flame trap and associated plumbing, or the crud that accumulates in the throttle body? Will that be reduced or eliminated by switching to synthetic?

I don't have a turbo on either of my cars.

It won't reduce liquid oil blow-by on a worn engine, but it will reduce the dried crud build up in the flame trap.

Rob,

There is an overwhelming bias towards Volvo (same as Mann) filters. They're just better. The same can be said for most Volvo parts.

Synthetic oil is recommended for any turbo, especially the oil cooled ones. Most use 10W-30. The heavier weights are not needed and may actually delay oil reaching everywhere on startup. The only turbo I had to replace was my first 240T where I used the 10W-50. One case doesn't make for a scientific study but I have had a half dozen others on 10W-30 without problems.

Skip

'80 242GT ProRally

'93 850GLT

I used 20w 50 synthetic oil this summer and it worked well. I noticed that the oil pressures were up a notch, and the car did very well otherwise. I am now using 10w 30 synthetic, which seems to be working well for winter. I would have used 10w 40, but there just wasn't any at the store (synthetic) that day.

If the truth be told that environmental impact costs of disposal were added to the price of every can of dino oil, I believe the costs of synthetic oil would be far less than dino oil; of course this would have to include the extended drain periods possible with synthetic.

I believe the extended drain interval is a no brainer...the real issue is leak control and lubricant contamination. If you can't keep the engine sealed, then changing the lubricant every 90 days or 3K miles is a good maintenance practice. OTOH, my new 2000 Audi A6 V8 4.2Q came from the factory with first oil change specified at 8000 miles on dino oil! It takes 8.5 quarts, and didn't use more than 1/2 quart by the time we took it in at around 8500 miles (and put Amsoil 15W-50 diesel/marine in it). It now has around 13K on it and hasn't used any oil and is still almost the same color as when it went in...an amazing engine.

I've done spectrometric oil analyses on several of my own cars and seen the results on literally tens of thousands of Army vehicles (OK, it's been ten years since, but I was there when Army Oil Analysis Program was implemented) that consistently confirm extended drain intervals, even with dino oil. We even ran tests at Fort Hood on 0W-30 arctic (synthetic...yes the army uses synthetic but only for arctic) oil vs straight 30W dino on a 1760 in3 V12 air/oil cooled tank diesel engine...virtually no wear in 110F heat in summer vs light scuffing with the dino oil. The reason the Army didn't go to synthetic was purely cost (it also didn't help the analysis that the general (get it?) consensus was that the stuff would simply get stolen and used in pov's too...something like the silicone brake fluid issue which exhibited remarkable shrinkage for the first few years...now everyone knows its problems....as well as contamination/leaks.

The general consensus is that synthetic is superior in every way to dino...run your own spectrometric oil analyses. Significantly less wear metal contamination, better viscosity control, better detergency, etc. I think the European nearly wholesale move to factory fill with synthetic is particularly signicant, not to mention Corvette ZR-1 and GM Syclone/Typhoon factory fill. Mastercraft ski boat engines were (are?) warranted for life to original owner, loaded with Mobil-1.

Only you can make the decision.

I've been running Mobil 1 15w50 in my 81 B21FT for over 6,000 miles with no problems, and I know there are others who have been using it for far longer with no problems. I do change every 3000 to 3500 miles because I'm paraniod and can't afford a new turbo or engine, but I know that some synthetic oil manufactuers do recommend longer oil change intervals. Amsoil does for sure. And Mobil 1 15w50 should be available, I see it all over the place in Washington and Oregon, so there should be some around in CA.

My local Volvo dealer has several filters cut apart in the parts department to show the differences, and I know I've seen similar displays in other parts places, but basically the visible difference is that the Fram filter is something like a 10 point star around the central core, and the Mann filter (which is the OEM Volvo filter) is something like a 30 point star, its a very impressive difference. I don't remember a size difference in Mann vs Volvo mine were identical, and the Fram filter I remember is a bit smaller than the Mann.

Good luck with your decision. I think the added security is worth it.

I'm pretty sure that Mann is the OEM supplier of volvo oil filters, so they should be the same in every way, except for the printing on the outside, and the price (I would expect Mann to be a little cheaper than Volvo). Here is a good site for oil filter information:

http://members.nbci.com/_XMCM/minimopar/oilfilterstudy.html

And specifically about the Fram filter:

http://members.nbci.com/_XMCM/minimopar/oilfilterstudy.html#fram

http://members.nbci.com/_XMCM/minimopar/oilfilters.html#avoid

To stir the pot even more: I just switched over to Mobil 1 in my 105k 240DL and was surprised to find that Mobil 1 makes an oil filter which fits. It was physically much heavier and also significantly shorter than the Fram/AutoZone type filter that the previous owner had in there. What is the opinions out there on the Mobil 1 oil filter?

Paul