Henry964

I was faithfully using Liquimoly 10w-40 Mos2 oil in my 964 but that german oil is no longer available here.

i still can get Motul brand oil and I was wondering if itīs better to use the 6100 10w-40 semisynthetic (called Synergie) similar to the oil I was using before, or the fully Synthetic 8100 Excess 5w-40.

My engine is untouched and with 102000 miles

Any opinions on this choice?

hamah

I'm hesitant to wade into this one as everyone has their own opinions on the matter. I certainly can't comment on these specific brands of oil.

I know many will not agree with mine. I run a good quality non-synthetic (20w-50 for my climate) because I believe it has less tendency to weep and because it is less expensive. Considering I go through a litre every 1200 Km or so I do go through a fair bit of it between changes.

I do run full synthetic on my other cars as they simply don't go through oil as fast (and I've run them that way since new).

Laker

can you get Motul 300V?

https://rennlist.com/forums/964-foru...-oil-2.html#16

Makmov

I switched to Valvoline VR 20W-50 which has good ZDDP numbers. It was like second or third to Brad Penn. For some reason most of the synthetics have had a dropping in ZDDP over the years. I guess it was to meet new GF-4 EPA standards circa 2006 they started stripping out ZDDPs from synthetics.

Since the switch I have had better oil pressure, lower oil temp, and less weeping.

Not that price was a factor but conventional oil was a lot cheaper.

And I didn't have to go through the brain damage of trying to find VR 20W-50 like i did with Mobile One V-twin, which I could find a couple gts here and a couple there. I ended up having to go to 5 places to round up enough V-twin.

I have on occation used Castrol, who invented ZDDPs, on other customer 911s.

For those who don't know what a ZDDP (Zinc dialkyldithiophosphates) is, it is a Zinc Phosphate compound used as an additive in oils specifically for the camshaft to lifter contact patch where high valve spring loads were found. The ZDDP was a sacrificial part of the oil film on these componets.

Mainly only required on older high perfomance type cars.

FeralComprehension

Name brand synthetic diesel truck oil can be a good fallback choice.

power_up

Using 300V 15-50W after this post.

Suncountry

Like Makmov I have been running the Valvoline VR 20-50 for the ZDDP properties in my 76 vette. It is the only one I could readily find with high levels of ZDDP for my flat tappet cam. I only put a few thousand miles on the vette each summer and change the oil in the fall. So it works for me. Since I don't drive it much (collector insurance limitations), my plan is to sell it this coming summer and start the hunt for a 964. In the mean time I will be learning what I can about the 964.

Henry964

Thanks for your help!!!
Valvoline was never available here, and regarding Motul 300V it is available here but is very expensive, I mean around 50 dollars the 2 liters can

KaiB

That's interesting - and for folks with no options perhaps a great hint.

Do you have data or a source...I'd love to know that this is true because it is such a great fallback.

FeralComprehension

I'll tell you what I think I know, but I want to preface it all with the observation that the same type of regulatory changes that drove ZDDP out of passenger car oil are being considered/implemented for Heavy Diesel emissions. Consequently, the available information may be out of date due to silent reformulations on the part of the oil manufacturers (much like those which sapped the love from Mobil 1...)

The two I use ATM are Mobil Delvac 1300 15w40 ($11-15/gal at Walmart) which is conventional, and Shell Rotella T6 5w40 ($17-22/gal at Walmart) which is synthetic. In my experience they mix well, so in the summer I run straight Delvac and switch to using the Rotella as a top-up as the weather turns cold. This is my first winter on the p-car, and I intend to do an analysis once I hit 10k miles on the oil to make sure that it's working as I'd like.

The forums at BobIsTheOilGuy.com (BITOG) is where to find the information we'd most like. I think you have to register to see them, but it's free, painless, and totally worth it. The forum of interest in this case is the 'Virgin Oil Analysis' thread, in which members post oil analyses of (wait for it...) virgin (=unused) oil to determine what the additives look like.

Unfortunately, the only virgin analysis for D1300 there is several years old, but I did find a more recent *used* oil analysis here (from '10) showing 1127ppm of Zinc, 870ppm of Phosphorus, and 1180ppm of Calcium.

The latest Rotella T6 analysis at BITOG is from July of '11 (here) and shows 1264ppm Zn, 1147ppm P, and 833ppm Ca.

Once I have my analysis done I'll post up.

Laker

http://www.lnengineering.com/oil.html#Z18

If it is CI-4 or earlier. CJ-4 and higher have lower ZDDP