Doug H

Just saw Loren post on Pelican parts about synthetics and Porsche's non-approval of regular oils. He seemed to say that synthetics were not good for older cars. He may have just been attempting to ruffle a few tail feathers which he accomplished, but I have considered going to Mobile 1 in my 964.

My shop uses Castrol 20W50. It does get hot and humid here during the summer. My concern was that my non-leaking engine may develop small leaks if I go with Mobile 1.

(1) Any thoughts about using Mobile 1 in our 964s.

(2) Any benefits performance wise using Mobile 1.

(3) What do you use and have you used Mobile 1 in your 964.

pete000

I use mobile 1 in everything including my lawn mower. It is really quite good oil. I am running 5-30 in my 964, I get it by the case at Costco. I have tried the 0-40 in my VR6 Corrado and was thinking the thinner oil might build a bit more power but its so thin it seeps out at the oil cooler lines.

It can take higher temps than regular oils. As for putting it in older cars I put it in my 90 Vanagon which has over 100K on it and it does not leak a drop! You can run more milage with the Mobile 1 I go 7500 on my van.

It takes two changes to get absolutely all the old oil changed due to the oil lines and cooler.

JoeW

I have Mobil 1 in mine, 10W30. Because EPE had it and used it when I had them do the car's first maintenance. No leaks. Joe W.

RSAErick

Amsoil 20W-50 Racing oil

I'm never sure how anyone "know's" their oil is good, bad, or other.... but I haven't had any catastrophic failures while using this oil.

Erick

Bill Gregory

Synthetic oils have been the standard Porsche fill since roughly the mid-1990's. Almost like Pete, I use Mobil 1 in everything (except the lawn mower), and specifically, I use 15W-50 in the 964. You can look at any oil manufacturers website to get a list of the benefits of synthetic oils.

Regarding the Pelican post that started your question, it's probably the same one posted on the Rennlist 911 forum.....there are some comments (one by me) that point out at least one plain wrong point in the post.

I've previously posted the Porsche recommendations for oil brands and viscosities on Rennlist. Regarding the fundamental question, if you want to use synthetic oil in your 964, go for it!

JoeW

I almost forgot to mention -- WalMart has reduced their Mobil 1 price to under $20 for the five quart jug, and Target has it on sale around here for (IIRC) $3.39/qt. Joe W.

garrett376

My 964 has had 20w-50 non-synthetic, but I just bought a case of the Mobile1 10-30 from Costco that I'll put in next month when I do my 50K service. I figure if it leaks, I can always go back to the non-synthetic. I'm counting on it staying dry! And I'm looking forward to the 12,000 mile change interval - although I'll probably change it at 3000 miles the first time, to get all the old oil out. Hate to have 3 quarts of dead non-synthetic oil in there for 12000 more miles!

On my 65 911 I wouldn't dream of using the synthetic, since it already leaks like a sieve!

Tom W

I use Mobil 1 15W-50 in both my p-cars.

garrett376

You guys who run the synthetic motor oil - do you also run Mobile 1 tranny oil?

I need to change my tranny and front diff oils at my upcoming, and curious what is recommended. I've used Valvoline Racing 75w-90 in my 65 911 and was thinking of using that unless otherwise recommended by you guys to use the synthetic.

PC2

I use Motul 6100 Synergie SAE 15W50

Kahdmus

Mobil 1 5W30 here!

springer3

I am using M1 5W30, same as the previous owner. Zero leaks, and runs like new. I also run M1 synthetic in the transmission - no leaks, and the shift action is fine.

I was a late convert, and still find it difficult to justify the additional cost. Conventional oils are now so good that wear is hardly an issue in modern engines. The seals are leaking and the valves need attention long before the rings and bearings need attention. I justify it by the extra margin provided if I run hard on a hot day, or I need to extend a change interval (on a trip, for example). There is a slight fuel economy benefit with sythetic oil.

Anyone saying that modern synthetics cause harm or are more prone to leak is simply wrong. Modern formulations do not attack seals. They can be mixed with conventional oils with no problems. Synthetics are actually thicker at high temperature than conventional oils, and therefore will leak at a slower rate.

Bill Gregory

Yes, Mobil 1 gear oil works well in our G50 transmissions.

dumluk

I'm a bit confused (no surprise to those who know me.) I've got M1 15-50 in my car now, but lately there have been reports of that product no longer being on the "Porsche Approved" list. It shows M1 0-40, but not the 15-50.

Explanations?

Bill Gregory

Dan,

That's correct, 15W-50 isn't on the Porsche list. If you look at the temperature ranges covered by the x-40 oil, you'll find that covers most situations a street driven Porsche will find itself in. I know many who use 15W-50 or 20W-50 take theirs on the track, where the elevated heat environment supports/demands the use of a x-50 oil. Temps in Florida may support 15W-50 for added protection on the hottest days, or especially if you go to the track.