What oil to use in '86 Porsche 911?

[DPDISXR4Ti]

Given that this is a flat-tappet engine, I'm assumming I should be looking at an oil that still has a higher ZDDP content, yes? I had been using Super-tech (Wal-mart) Synthetic 10W-30, but I'm wondering if one of the Rotella T oils might be a better option (they still have a reasonably high ZDDP content, right?).

The car is generally put away for the Winter - in fact, I'm about to do that now, but wanted to do an oil change first. It only gets maybe 1000 miles/year, and hasn't seen the track in years, so no need for anything exotic. Protecting the engine is my biggest concern, given the cost of a rebuild on these wonders.

 

[Auto-Union]

I'd consider Mobil 1 10w-30 Hi-Miles, SL. Rotella TS is a great choice though.

 

[uazj1]

Check you owner's manual, I doubt 10w-30 is the ideal weight. Most Porsche guys run 20w-50. I run Mobil 1 Extended Perf. 15w-50 in my '86 944 Turbo. I know the Lubro Moly 10w-60 is popular.

 

[Loobed]

20w-50 is what the manual (1984) says to use .

mine needed 12 quarts for a change, so I just used any name brand dino oil. 12 qts of synthetic was too much for 3000 OCI.

The 15W-50 Mobil1 that was mentioned sounds like a good choice if you dont mind paying $80+ for an oil change.

I always bought what was on sale for under $1 a quart
Chevron
Castrol
Havoline
Shell
Pennzoil
etc

 

[oliver88]

You do not want to use the 30 weight oil in a 911...very few,if any, 30 weights have the HTHS required for Porsche engines...Minimum is 3.5. I have used Rotella T 15w40 and Delo 400 15w40 with tremendous UOA's in the past...Most "fleet" HDEO's will be fine for that engine...There is an extensive list of Porsche approved oils if you "Google" it. Hopefully Doug Hilary will chime in here!

 

[Merkava_4]

***Cue in the Rocky Balboa music***

 

[tom slick]

I know that 15w-40 was fairly popular in PCA racing a few years ago.

 

[02zx9r]

Originally Posted By: Merkava_4
***Cue in the Rocky Balboa music***

Gotta be SL, I have a 5W30 with the old label like that , is SL as well

 

[Merkava_4]

I'm thinking it doesn't need to be SL for being such a heavy grade that it is. Someone on the board posted a Castrol approved oil list for older cars and I remember it having SM oils that were all xxW40 and thicker it seems like.

 

[Doug Hillary]

Hi,
Brad - oliver88 has already said it all. A good common Branded 15w-40 "mixed fleet" HDEO such as "oliver88" uses is an excellent choice. The ambient spread is 15f to >100f for a 15w-40 viscosity

If you operate in colder (or hotter) weather then a synthetic "mixed fleet" 5w-40 such as Shell's Rotella "T" is the best choice (there are about four Brands available)

SAE30 oils are not for Porsche cars (well, except the V6 (VW) Cayenne)

Regards
Doug

 

[02zx9r]

Actually I did not mean that the oil he uses has to be SL, just meant that the particular picture of the synpower 20-50 you posted was an SL oil, maybe

 

[02zx9r]

I would agree with the hdeo 15W40's

 

[Merkava_4]

I don't know how you're able to tell if the bottle is SL or SM unless you have some kind of special software that is able to turn the bottle around in the picture.

 

[02zx9r]

Just a guess because I have a 5W30 with the same older label and it is SL, so was just assuming that this is SL too

 

[DPDISXR4Ti]

Originally Posted By: Doug Hillary
A good common Branded 15w-40 "mixed fleet" HDEO such as "oliver88" uses is an excellent choice. The ambient spread is 15f to >100f for a 15w-40 viscosity

If you operate in colder (or hotter) weather then a synthetic "mixed fleet" 5w-40 such as Shell's Rotella "T" is the best choice (there are about four Brands available)


Thanks Doug - looks like we're having this conversation in two places! It's not clear to me why Charles was so anti CJ-4 oils, other than perhaps he doesn't sell any. D'oh!!!!

Incidentally, I also own an Alfa 164 with the 3L V6 flat-tappet motor. I'm thinking the same oil type would be a good choice here, yes?

 

[Towel_Rail]

Let's add to the fire a little.

http://www.lnengineering.com/oil.html

- Scott

 

[Doug Hillary]

Hi Brad,
yes an excellent oil for the Alfa indeed! The V6 engine is a true masterpiece and I'm sure you enjoy it. I have driven a few 164s. I'm a a true Alfa fan having owned a 1600 Giulia Super TI (in 1971) and some 1750GTVs. I once had a Lancia Fulvia Coupe too - it was a magnificent little car

Scott - Brad has alluded to the Link by refering to Charles in his Post - we are very aware of it thru Porsche circles but thanks anyway

Regards
Doug

 

[Auto-Union]

Originally Posted By: oliver88
You do not want to use the 30 weight oil in a 911...very few,if any, 30 weights have the HTHS required for Porsche engines...Minimum is 3.5.


Wow, well umm...guess what the HT/HS of M1 10w-30 HIGH MILES is. Hint- it carries A3 spec.

Porsche approved a 30 weight oil, GC. HT/HS there is no mystery, 3.5cP. What's the problem there? Same HT/HS as M1 0w-40, but if that was recommended people would fall over each other to say how great a choice is. In an older engine? I don't think so.

Anyone looking up the additive levels of the M1 High-Miles or doing any research before posting, or are those days of BitOG long gone?

M1 10w-30 HM is SL for a reason, more additives so it's compatible with older engine design, like the original poster's.

He also did mention wanting to avoid a rebuild, hi-miles oil can only be of benefit with those older seals. Right...?

Are we all taking into account that the guy lives in New York and it's coming into winter? The guy went out of his way to say he did not track or beat on his car. 3.5cP HT/HS is fine.

Seems like a very good choice considering the $4/q price tag along with the sump size on that engine. If it burns a lil oil, use the 10w-40 HM. Problem solved.

 

[Auto-Union]

HM oil = an oil actually working while the car sits.

 

[Doug Hillary]

Hi,
IMHO and in such cases where storage protection is required a "mixed fleet" HDEO with a Vapour Phase Inhibitor is the best bet

Regards
Doug