Easy ??? Which oil to use...

Looking to put mobile one in my 70/71 E.

What are the differences between viscosity in the mobile one line (10W -50 vs 5W ???).

Which one do you recommend I use?

Thanks

I don't think you will be happy with either one ... it oozes out a bit too easily in my experience! But, if you must, 15-50 would be most appropriate.

I had ALL of my major oil leaks fixed and no dripping at all with Valvoline Racing 15W-50, when I was seduced by the Mobil 1 song, and will be going back to the Valvoline in a few weeks.

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Warren Hall
1973 911S Targa

To expand on this topic, if I may...

What about those old non-synthetics? Any experience/recommendations on what to use or what to avoid?

Brian
91 C2

I've looked into this motor oil thing and find that

1. Synthetics tend to make older cars leak oil. I would only consider using a synthetic if the engine was just rebuilt (all new seals), but even then, the seals and mating surfaces may not be designed (even if they're new) for synthetic oil.

2. Synthetic oil is very spendy, and my car takes nearly a case of oil per change. I would not leave ANY oil in my car for too long.

3. Valvoline seems to be at or near first place in every testing lab's ratings of oil. A case of Valvoline racing 15-50 is waiting for me to finish making mistakes on my clutch job.

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'83 SC

I have had NO bad experiences with petroleum oils, but my experience has been limited to Castrol GTX 20W-50 and Valvoline Racing 15W-50 over the past 25-30 years!

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Warren Hall
1973 911S Targa

I switched to Mobil 1 on the last change, and have had no leaks in my 86 Targa.

It runs no differently that I can see, but if it protects the motor better, which it does, it's worth the $50 for an oil change. I love my car that much; it's worth it. I will let the Mobil 1 stay in there for 5000 miles and change it. Two oil changes per year, approximately.



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Mark Szabo
1986 911 Targa 3.2

I started using diesel motor oil 20w-50 and they are great. My car on traffics got hot as 120 c. and the oil didnt get as thin as the other oils. And its stays with its original color and texture for much longer. I realy liked it.
some one has any advice for not using diesel oil?

MMBRAZIL: That's interesting. I've had those oils recommended to me by heavy equipment mechanics who insist it is the best. But these oils don't seem to get rated when labs test oils. Chevron Delo 400 is an excellent oil, according to these equipment mechanics.


Mark: I can't disagree with you. Not even one little bit. I love my car too.


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'83 SC

MMBrazil,
did switching to the diesel oil make a difference in temps?

jryerson
I noticed very little diff. but the time I changed it, my car was running lean....

Anyone have comments on the "blends", that is the oils that are part synthetic and part petroleum based? I just started using Castrol Syntec in my '72 911T and it appears to be a good oil.

Keep the information on diesel oils comming. A long time ago I worked for ryder, with their lease account semis. I think we ran 8K between oil changes. I know 14 liter cats and cumming use about 48 qts for a change. I have to think these oils have some good additives to because they have to deal with lots of carbon and probably sulfer contamination. I just remember the stuff got very black, but a cat would go to 500K before needing a rebuild. Just some thoughts.... david

I have been using the Castrol blend and the Valvoline blend since purchasing my car 2 years ago, the oil stays clear longer and seems to protect well but I have experienced a few leaks from my pressure sending unit and oil light sender along with other areas which I suspect is due to the synthetic
I like the idea of the semi synthetic especially here in the desert where temps get to 120'+ for the extra protection and when oil leaks occasionally on the exchanger it doesn't burn (smoke) as quicky or as much

I agree with Warren, Castrol 20/50.

We are very simple on sythetics, if you use syn. on any of our motors we will void the warranty we are sooooooo against it. It leaks and wait until you see all the 3.6's needing camshaft repairs from only using the stuff. We have done many 3.6 rebuilds and the camshafts are wearing WAY to quick!

Roy at http://www.motormeister.com

Seems like alot of the 911/914 crowd are using Swepco 201 in their transaxles, has anybody used their motor oils and if so what are your thoughts? Pete

I think I am against the Synthetics also. When I purchased my car last Dec there were no indications of recent leaks either under the car after it set in the same spot or on the engine. I changed the oil soon after I bought it and about 1000 miles later found spots on my garage floor. The spots got worse. I am about to change the oil and check the valve adjustment and will put Castrol GTX 20W/50W in the sump. Call me paranoid but I will probably not wait too long after the first change to make a next change. I use the old addage that there are deposits left behind from one type to the next, kind of like flushing radiators.

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John Birkett
72'T Targa

A mechanic I know uses 15w-40 Valvoline only, and in every car he works on, unless the owner specifies otherwise. I've asked him why, and he says, this is the only oil that's viscosity is close to (15-40) what it should be, naturally, and therefore it doesn't have as much additives in it as another type of oil. He doesn't use sythetic, and only valvoline, claims that they get the crude from the US (mid western) and it's the cleanest, or purest available today. The oil that comes out seemed to be a tad cleaner when I tried this oil in my car, but not a huge difference, I won't comment on this issue because I don't know anything about it, but thought it'll be nice to pass along.

I have used Mobil 1 15-50 in my 78 SC for about a year now (3 oil changes). No leaks, no problems. I did, however, immediately notice an improvement in smoothness and throttle response, as did friends who drove the car. For me, the benefits of synthetics outweigh the risks. A question to the post above about 3.6 cam problems- why would a slipperier oil with superior wear characteristics cause cam wear in a 3.6, an engine that came from the factory with this oil in the first place?

Serge--here's a cynical suggestion: If you're a shop that does rebuilds, the last thing you want on the customer's floor after he takes the car home is oil. Synthetics, although offering superior wear characteristics, are more likely to reveal less-than-tight rebuild jobs. Hence, "we'll void your warranty if you use an oil that might demonstrate that our rebuilds aren't as good as they should be".

If the factory recommends Mobil 1, then this stuff about "cam wear" is highly suspect to me. I own a 930, and before that have had turbo cars for many, many years. I always run synthetics--in my case, Redline or Motul. I don't blame my oil for leaks; I look for the usual suspects, and I use oil leakage as at least a possible sign that any work I or any one else did wasn't up to snuff. And I certainly don't blame my oil for engine wear.

I have heard that synthetics get very thin when hot so you have much less of a cushion between parts which would lead to heat and wear
It would be nice to know the true un-biased
facts though