Sorry, another oil question for a newbie

[rolls 912]

I have a well used 3.2 Carrera in good condition running in temps from 5 to 40 degrees (41-104F). Usually driven reasonably hard. I was told to use liqui molly 5W-40 top tec.
Does that sound about right?
Cheers

[trond]

Love oil discussions and this is the place to be for those
liqui moly rep here (sitting in Germany) said to use only #1092 10W-40 leichlauf MoS2 because of the antiwear properties with all the molybdenum (oi is dark grey). They advised against synthetic. Others have received different advice from liqui moly. I had problem with dropping oil pressure at higher engine temperatures (logged oil temp was around 212F) and ended doing a roadside oil change to 5W-50 synth


Steffen Niemietz
Attachments
Tue, Jul 24, 2018, 10:32 AM
to me

Hello Trond,

unfortunately we don´t have a fully synthetic SAE 5W-50 in our product range and still do not recommend to use fully synthetic (PAO base stock) in your 1980 Porsche. As mentinoed already it may cause a material incompatibility.

Our recommendation is still to use our #1092 MoS2 Antifriction 10W-40, further you can add our Viscoplus for Oil (product information attached) if neccessary under extreme operating conditions.



Best regards

i. A. Steffen Niemietz
Anwendungstechniker
application engineer

F & E / Anwendungstechnik

Phone: +49 731 1420-658
Mobil: +49 162 2815064
Fax: +49 731 1420-44658
steffen.niemietz@liqui-moly.de

LIQUI MOLY GmbH
Jerg-Wieland-Straße 4 | 89081 Ulm | GERMANY

[OldSpool87]

Most run 20w50 weight. I have a 930 that gets a synth 20-50 and an SC track car that gets a 15-50 Motul something or other. I spent a lot of time hand ringing on which was best pouring over all the oil threads. I concluded that the best thing was to find an easily accessible oil that I could use in both cars and settled on VR1 race synthetic 20/50. With this simplified view,I now have a lot more free time and the nightmares have stopped.

[mikedsilva]

Originally Posted by rolls 912

I have a well used 3.2 Carrera in good condition running in temps from 5 to 40 degrees (41-104F). Usually driven reasonably hard. I was told to use liqui molly 5W-40 top tec.
Does that sound about right?
Cheers

Have you considered Penrite HPR20w60? We can sometimes get 5litres for $32 from supercheap.

[Bill Verburg]

Originally Posted by rolls 912

I have a well used 3.2 Carrera in good condition running in temps from 5 to 40 degrees (41-104F). Usually driven reasonably hard. I was told to use liqui molly 5W-40 top tec.
Does that sound about right?
Cheers

When new you car was spec'd to use API SE or SF oil, SAE 10w-50, 15w-40 or 20w-50 15w-50 was later added

the above weights are for normal warm weather operating conditions

SE and SF oil is no longer available, the current spec is SN, the weights are still current

The major difference wrt our cars in oil composition from SF to SN was the reduction of anti wear additive P & Zn aka ZDDP This reduction occured w/ the SJ oils introduced in 1996 and continues to this day. But not all oils are subject to mandatory ZDDP reduction, The weights listed above can use what ever ZDDP levels that the manufacturers choose.

With that in mind look for an oil w/ the above weights and w/ ZDDp comparable to that seen in SF- SH oil, ie 1100-1400 ppm Z, P or ZDDP

Some of the newer oils are also using Boron as an anti-wear component, this may or may not work out well, The jury is still out on that.

[kyngfish]

Funny - the Liqui Moly rep here recommended their Race Tech GT1 10w-60 and their ceratec additive. I live in warm weather (Florida), and I like the idea of oil that flows quickly at start, and has the higher viscosity when warm. I'm not an engineer, but since I've prepared my mind and budget for a rebuild anyway in 2020, I figure, it's as good a time as any to see if the newer oils and additives can extend that timeline a bit.

I'm worried about the Ceratec creating blockages - so I used their MoS2 additive instead. Made the switch over the weekend. I'll know in a few thousand miles if I like it or not .

I know the ZDDP debate is endless, and profound, and that you need a PhD in motor-oil in order to make sense of it. But if ZDDP can coat and protect, why can't something else?

[SalParadise]

Originally Posted by kyngfish

Funny - the Liqui Moly rep here recommended their Race Tech GT1 10w-60 and their ceratec additive. I live in warm weather (Florida), and I like the idea of oil that flows quickly at start, and has the higher viscosity when warm. I'm not an engineer, but since I've prepared my mind and budget for a rebuild anyway in 2020, I figure, it's as good a time as any to see if the newer oils and additives can extend that timeline a bit.

Yeah, in a new 2019 911.

The aircooled 911 engine design details date back to the late 1800s with Karl Benz and the flat VW four of the 1930s - and pretty much did not change for 100 years. I would not run such a thin oil with such a wide viscosity range (especially in hot climates like Florida).

I'd run 20W50 of any brand. Or straight 50W. Any brand that suits you. If you want to run your 911 in cold climates like Michigan, run 15W40 in the winter.

These cars like heavier oil.



These are old engines of old design.

[kyngfish]

Originally Posted by SalParadise

These are old engines of old design.

Not gonna jump into how many different things are wrong with your post. But considering that the oil Porsche itself is marketing for these cars is 10W60, I'd just say that clearly... it's up for debate.

As you correctly noted the winter dual viscosity oils have a lower high and a lower low number because the numbers are correlated, not because 40 all of a sudden becomes optimal in winter time, rather, because you want the lower cold viscosity and the 40 comes along for the ride. I'd only posit that just because the latest thing ten years ago was 20w50 Brad Penn - doesn't mean it's the latest thing now OR the best.

Happy to be the guinea pig. I'll let you know how it goes, in a separate post.

[rolls 912]

Thanks for all of the responses. A wealth of knowledge as always.

Reading them, I still find it difficult to deduce which oil weight (and brand) is best. Is 10W 60 the right one?

(It baffles me that Wayne has never created a definitive sticky produced by an engineer that states we at Pelican believe X weight oil is best, and these are the best brands. Period. It is the one issue that causes so much confusion and conjecture. Especially for the less technical folks.)

[kyngfish]

Hah - as you can see - complicated question.

The accepted belief is that you need two things - the right level of ZDDP and a thicker weight oil. Most people on here swear by Brad Penn 20w50 or Valvoline VR1 which are non-synthetic oils.

Another common belief is that synthetics will swell your seals and cause leaks - and if you want to play it safe, that's that this board would recommend. Other people say synthetics used to have this effect, but not anymore.

If synthetics don't scare you off, 15w50 Mobil1 has the right ZDDP and a better cold viscosity. Anecdotally, I've been using 15w50 M1 without any leaking.

For someone just getting into this - I'd recommend sticking to what the generally accepted practices are.

For me personally - I'm going to pony up the funds for a rebuild sometime next year, so I don't mind testing something else, I just switched to the Liqui Moly 10w60 and added MoS2, mainly because I believe the lower cold viscosity is better for startup, and I believe new anti-wear components are going to perform as well as ZDDP long-term. At worst, I'll still rebuild next year, at best the 10w60 with MoS2 will extend the life of my engine. Either way I'm not a mechanical engineer or otherwise, just going on what I know and what makes most sense. The Porsche classic oil for 3.0 engines and up is 10w60 synthetic - so do with that what you will.

[Trackrash]

For many years I used Rotella 15-40 dino Diesel oil. Perfect for our cars, however, it has been re-formulated and to make matters worse Rotella now has like 5 different flavors.

If you search you can still find the old formula.

[gomezoneill]

Use a quality oil and change it often. All you need to know.

[pmax]

^^^
Yes, that's key, regular oil change. To state the obvious, antiwear components in the oil wear out with usage.

A great thread, make sure you read thru all of it.
https://rennlist.com/forums/993-forum/863862-porsche-classic-motor-oil-explained-by-porsche-guys.html

The 540rat blog is also quite informative. Take the rankings for what it is ... one guy's independent but consistent oil testing results and draw your own conclusions.
https://540ratblog.wordpress.com

[Dodge Man]

ZDDP is the additive for cam/lifter interface life. Most diesel oils have ZDDP levels good for "High Pressure" rockers(Porsche 911) and "flat tappets". Valvoline VR-!, Brad Penn, etc... takes care of business here. ZDDP additive is also available in bottles at most parts stores.

IMHO: Do your homework and make yourself happy. It's your money.