Made the move to synthetic....

1982911sc · 11-14-2004, 06:58 PM

OK, I know this topic has been beaten to death, but I will report out my real world findings on switching to synthetic oil in my 82 SC.

I went with Mobil 1 15-50...switching over from Castrol 20-50..Since I was switching I also decided to pull the sump plate to take a look for any dreaded metal debris...very happily found nothing.

After the change I took the car out for a very spirited test drive, stopping early in the trip to check and add oil to the proper level. Although, most of this may be psycological the car seemed to run better, more responsive, and smoother, the exhaust seemed a tad louder as well. The car definitley ran cooler, it was a cool day anyway, but I never saw temps above the second white mark and this was running hard on the expressway for a good 30 minutes.

It has only been one day and I am VERY curious to see if any of the "leaking" stories come true. One thing I will note, on the oil bottle itself it says that this formula has been "tested for all seals" or something like that. Which I would say is speaking directly to the older car owner. We will see I will let you know if my garage floor ends up looking like the Exxon Valdez has paid a visit!

duke3282 · 11-14-2004, 07:19 PM

I switched to mobile 1 the first time i changed my oil. I saw the same results you did, however the only one I can prove is the temperature reduction. It definately runs cooler, almost never gets out of the white section. I have been using it for 2 years and havent noticed any leaks, only goes through a quart or so every 3000 miles.

1982911sc · 11-14-2004, 07:27 PM

Duke,
What year and model Porsche are you running and I assume it had Dino oil before?
What viscosity Mobil 1 are you running?

duke3282 · 11-14-2004, 07:52 PM

81 sc, i believe the guy before me used castrol 10w50 or something like that. I use the mobile 1 15w50, the one with the red cap. Its pretty expensive but i think its better for the engine, and probably cheaper in the long run.

chuckr · 11-15-2004, 05:10 AM

I put Red Line 20/50 in my 83SC at 160,000 miles. The P.O. had
Valvoline 20/50 and my mechanic suggested that I not use
synthetic. I had NO problems... good gas milage and good
performance. I dyno'd the car @200,000 and got 183hp
at the rear wheels on a stock unopened engine, upper end done @
111,000 before I bought the car. I totaled the car @ 250,000
still running great but starting to smoke a bit on deaccelaration
I was saving up for a rebuild. Synthetics are the only way to
go !

RickM · RickM's Garage

I'm a Mobil 1 fan.

They do state on their website that Mobil 1 does not contain seal or gasket swelling ingredients as dino oils typically do. They also say that M1 does not create leaks but will leak through existing ones....and from what I gather it will probably leak more profusely.

Jim Richards · 11-15-2004, 05:42 AM

I switched to Mobil-1 synthetic during the summer and my 73E began to leak like a sieve. After this winter's planned rebuild, I'll stick with dino.

joeclarke · 11-15-2004, 05:47 AM

In contrast my experience with Mobile 1 is the opposite (of 1982911sc's).

Twice I have had wrenches put synthetic in non-leaking 3.2 engines (80k and 120k) and have seen immediate (couple of months) case leaks develop.

I have been closely associated with the refining industry for a few years and have seen lots of technical stuff on syn oil vs. dino. The most impressive of these is a video on lubrication in the valve train of a V8 when cranked in sub-zero temp. You'd use nothing but syn and/or always plug-in your block heater if you saw how long it takes dino oil to flow to the top of an engine at those temps.

But ignoring sub-zero conditions; with frequent oil changes dino oil gets the nod over synthetic for me. Cheaper, technically equivalent in the 99th percentile and wont turn my engine into a sieve.

Like the man said -

"Although, most of this may be psycological the car seemed to run better, more responsive, and smoother..."

I find the same when I move from 20W-50 in the summer to 15w-40 in the fall. Or even when I give the car a good washing/waxing - then it seems to really rip up the asphalt. Investments of money and/or sweat always make a car run at least one notch better...

RickM · RickM's Garage

I've been running M1 in my '85 for many years with no leaking problems at all.

Wil Ferch mentioned that Rotella Syn (IIRC) oil does not leak or leaks very minimally.

1982911sc · 11-15-2004, 06:06 AM

I guess only time will tell on the leaking, this morning I noticed nothing new.....I can state the temperature reduction is factual....Probably 10 degrees cooler or so......But if I do begin to leak....it will be back to Dino. My wrench, who services many, many older Porsches was very insistent that I give it a try (I change my own oil, I use him for bigger jobs)...we will see!

Vipergrün · 11-15-2004, 08:00 AM

Mobile 1 in my 80SC for over two years now, no leaks at all, no smoking, in fact, don't even burn much. Also use the Moble 1 oil filter instead of a Mahle. That adds 10HP

Jim Garfield · 11-15-2004, 08:04 AM

1982911sc - How many miles on your car? I switched to M1 when there was about 50k mi. on my 3.2. Three years later I don't have any leaks (knock on wood) and use a qt. every 3 - 4k mi.

Joeaksa · 11-15-2004, 08:08 AM

Have used Mobil 1 for years in several 911's with no leaks.

It does run just a bit cooler but the real benefit is that if I get stuck in a traffic jam I no longer sweat when the oil temp gets above 230 or so like I did with dino oil. Syn oils will take it up to 240-250 then its time to turn the a/c off and sweat it out.

JoeA

kach22i · kach22i's Garage

Synthetics run cooler, but they made my car leak.

I think regular gas makes my car run cooler too, but I'll stick with the 93 octane.

1982911sc · 11-15-2004, 08:20 AM

Jim, to answer your question. My car is an 1982 SC with 77,000 miles, with no major engine work ever needed-has all updates. Car has been very well maintained...with Dino the car had a very, very small leak out of the rear main seal...about a dime sized drop every week or so. My oil consuption is also very low, I think a add about a half a quart every 1,500-2,000 miles or so.

RarlyL8 · RarlyL8's Garage

Mobile 1 cause several small leaks to become about 3X larger (in volume). I gotta go back to frequently changed Dino. Leaks are not acceptable.

diy83sc · 11-15-2004, 05:34 PM

I had Rotella T Full Synth 15-40 in my 80 911 ... began to leak a drop or two on the floor after a few days. This happened shortly after the third oil change. Before, the case was moist with grime. So, I believe the synthetic found it's way through the existing leak?

Wil Ferch · 11-16-2004, 06:06 AM

Diy83sc:

What? Rotella-T comes in two flavors, AFAIK...
- 15W-40 dino
- 5W-40 synthetic ( or "pseudo" synthetic)

Which?

Wil

edward993 · 11-16-2004, 06:37 AM

Question:

If the engine has been accustomed to running dino, then develops a leak with synthetic, will switching back to dino bring you back to its previous state --i.e. small leak or dry when you had run only dino?

I'm interested in switching from dino to syn on a 3.0 with only 12K miles on a full rebuild w/seals etc., mainly because this is a 98% track car and I'm interested in high-temp "insurance." The engine is now dry but hate the prospect of developing a seep. Opinions ?

Edward

RickM · RickM's Garage

Quote:

Originally posted by edward993
Question:

If the engine has been accustomed to running dino, then develops a leak with synthetic, will switching back to dino bring you back to its previous state --i.e. small leak or dry when you had run only dino?

According to the Mobil 1 site dino oils contain gasket and seal swelling ingredients that Mobil 1 does not. I'm not sure if other synthics do.