15-50

 

Or 20W50 Mobil Twin-V.

 

 

For temps mostly above 50F my owners manual and the Factory Shop manuals recommend 10w-40, 15w-40 or 15w-50
the big concern these days is ZDDP levels, you generally want P & Zn to be between 1100 and 1400ppm unless it's a break in oil which wants to be in the 1700 to 2000ppm range

more ZDDP is bad at some point, according to industry testing levels of Zn above 1400ppm increase wear.

Typically break in is where you want increased wear to occur, break in oils want > 1400, they are usually in the 1600 to 2000 range. These are used for a very short time and then replaced by oil designed for longer term use.

M1 15w-50 is a great choice

Zn is the active ingredient, it's anti-wear properties are activated by heat and pressure and the Zn is lost to atmosphere in the process, ZDDP is a molecule which contains Zn and P, High P levels are what over time poison catalytic converters. Modern Starburst oils all have greatly reduced ZDDP to keep P out of the exhaust. Non Starburst oils like racing oils and severe duty oil such as M1 15w-50, Joe Gibbs, Brad Penn, Penngrade et al have 1100 -1300ppi ZDDP. Which is what you want.

 

From the Oracle at Mobile 1:

2018 Mobil Oil Chart

 

So check out the zinc/phosphorus levels of the M1 15-50, in the chart I've uploaded... Right in line with the zddp levels Mr. Verburg speaks of.

As Bill states, too much zddp will also prematurely clog your catalytic converter.

So if you get scared into running Mobil 1 V-Twin, I would like to suggest you at least 50/50 mix, with the Mobil 1 15-50... but this will still be on the high end of the spectrum of zddp content.

Anyone else puzzled as to who and why the Mobil 1 V-Twin oil was pushed so aggressively in the 993 forum? Not me, and not any more!

 

The P in ZDDP will poison the cats(if you still have them) over time but too much ZDDP(actually the Zn) is as bad as too little for wear as well.

 

Since we are discussing oil. What do intelligent minds think about oil additives? I have a long time mechanic, who swears by Lucas Oil treatment.
He has his own shop, plus does a lot of marine work. Every time he changes my boat oil, we go round, and round because I won't let him put it in. I feel if manufacture
felt the need, they would specify it. What do you think? His argument is cold starts. Better on engine with the additive.

 

I use 5w-40 Motul.

 

How high are t he ZDDP levels in the Porsche Classic 10W 60 oil that I havd been using since it was released in my -94 Carrera?

 

Use the proper high-quality full synthetic oil. Change it every year and every 5000 miles. Skip the oil additive.

 

I have never worn out an engine yet, ever, with any car I have owned, that's a lot of cars, including a 924s and two Carreras running the odometer up to 120K+ on some. I just use a good synthetic labeled Mobil 1 so I can't speak to the benefit of an oil additive.

 

 

I had a '85 GTI , I bought in '87 with about 45k in miles on it. Switched to Mobil 1, then put around 200k on it. It wasn't until around 180k miles that it would use oil between 6k oil changes ( around 1/2 to 3/4 quart). When I had the head pulled (for port and polish, cam) at around 220,000 miles the shop said they had never seen one with that many miles so clean.