Alan

I don't know about quieter but Vs. the same Mobil 1 15W50 it maintains better pressure and does not get as hot (which was quite unexpected...), I have a pan temperature gauge and that was quite clear.

My belief is that the AMSoil foams/airates less - because it also helped with (slightly) reducing oil ingestion. Less foaming may allow better heat transfer.

In any case it works better than any other oil I've tried.

I do also have a dual oil cooler: oil/air -> oil/water and my (added later) vacuum pump system further reduced oil temperature - also helps pressures.

Alan

UpFixenDerPorsche

Well I'm 'happy' with my Delvac 5W-40. (grabs volcano suit).
(which wasn't around 25 years ago and is a Group 5 PAO/ester oil).

'Happy' meaning that in 40C temps, my gauge shows 5 bar over 3k rpm and 2.5 bar at idle. No lifter noise on startup. 240,000mi

Will be doing a UOA soon. I'll post the results.

.

JET951

Every summer we get ( new to us ) customers in their 928/S/S4/GTS or 944/S/S2/951/968 or any air-cooled 911( last century Porsche's ) that has been driving around the city/suburbs for a few hours or more & they either contact us by phone or just drop by our workshop with one comment " is is OK that my oil pressure warning light / oil pressure insufficient display " is on when their Porsche is at idle ?

Naturally the answer is NO ( thats why its a warning light / display)

And when we enquire with the question } what oil viscosity do you use , most simply do not know or not sure , most of the time ( looking at previous service invoices ) we see mostly oil viscosities of between 5w-40 & 10w-40 , once the oil is replaced with 20w-50 , the low oil pressure warning at idle when engine hot never returns , but then again Porsche did print in the owners manuals that came with these cars ( all )in the mull grade "look at me centre section " , that between minus 10 deg cel to unlimited high ambient temp use 15w-50 or 20w-50 , all fairly straight forward & an easy issue to rectify , because the owners manual gives the answer & when I worked at a large Porsche dealership for many years prior to 1994 we only ever used 25w-50 or 20w-50 engine oils & we never ever had oil pressure issues or no 2 & 6 conrod bearing failures ( 928 all ) & no 2 conrod bearing failures ( 944 all )

The other big problem using a 5w-40 is in medium to high ambient temp rangers ( 20deg cel - 40 deg cel )= 68deg F to 104 deg F + and with the engine oil at operation temp range of 85 to 100 deg cel( 185 F - 212 deg F + ) is that the oil pressure is way too low at all RPM & the 944 series ( all ) + the 928 series ( all ) suffer aeration in the oil pressure circuit that tends to feed no 2 conrod crank journal on the 944 series & no 2 & 6 on the 928 series , so at the oil temps given above or even worse higher oil temps , one can not go for full power ( max RPM ) without risking or usually damaging these conrod bearings

How do we reduce / eliminate this risk ( without a major redesign of the engine ) = easy , one just reads the owners manual & in those ambient temp rangers use a 15w - 50 or 20w-50 ( we tend towards the 20w-50 our temp conditions .

One of the first times I heard of a 928 destroying the crank / no 2 journal was when we came across to what would be a new customer to us( this was years & years ago ) who had a 928GT ( 1990) and before we knew the car , the previous service provider ( Porsche dealership ) has installed a 5w-40 engine oil in it ( so called full synthetic ) , (Charles) the owner of the GT loved to boy race the car on the street & one afternoon he was giving his GT full revs 2nd gear chasing something like a WRX & he blew the no 2 conrod bearing / journal on a public road , I was intrigued by this to say the least & I wanted to know why , obviously the so called synthetic engine oil did not protect the no 2 crank journal / bearing , so we realised it was the lack of oil pressure at this journal that was super critical

Since then we have had numerous fellow members of the PCNSW that at track events had destroyed the same thing ( no 2 & 6 on the 928 series ) & no 2 on the 944 series , I can remember vividly one chap who used to compete in his 928GTS Auto ( This is just club stuff ) & I was walking past his now idling GTS after he pulled in after being out on the track for a few laps & he was idling his car & and I heard the hydraulic lifters clattering away , I couldn't help wanting to look in at his instrument panel & glowing like a Christmas tree was his large instrument display ( in big red lettering )" Oil Pressure Insufficient " & this engine was on a 10w-40 engine oil at the time ( I know I asked the owner ) & yes at the next track event he blew No 2 conrod journal/bearing , this was so violent the conrod completely came apart

This was completely avoidable by looking at the owners manual & using common sense by whoever changes the oil

As a matter of interest , on the track ( club events ) we only use a racing oil with a min viscosity of 25w-60 & providing the old conrod bearings are not previously damaged or worn & the conrod bolts are not previously stretched we do not loose any engines on the track or street for that matter & I will keep telling as many as who will listen so as we try to keep these unnecessary engine losses to a minimum

And yes using a dedicated Diesel oil like Delvac ( 5w-40 viscosity ) in ambient temp rangers like Australia is not ideal ,because dedicated diesel oils are very high in detergents & this makes the engine oil foam way too much at the higher RPM spectrum which only amplifies aeration to no 2 conrod journal , but if one is careful not to rev it out & does not get stuck in grid lock traffic for hours at an end , then you might be OK but you can not go for max RPM when the oil is hot

The last thing to Remember is that both Porsche & Mobil do Not Recommend the use of a dedicated/ primary diesel engine oil( Like Delvac) in a petrol ( gas USA speak ) engine , thats why Mobil like all other oil companies make engine oils for petrol powers cars ( less detergents = less foaming at high RPM)

But the one thing I do like about Delvac is that its a very good diesel oil for big low revving rigs & this very high quality ( proper Synthetic diesel oil ) has or at least used to have very high levels of ZDDP , and that brings me back to the question } Why do very high quality engine oils like Delvac which is what I call a proper synthetic ( not hydrocracked ) have any last century "Dino " WWII vintage ZDDP ?

I thought proper synthetics did not need this way out of date anti wear additive , if Delvac had no ZDDP would it still work to keep metal parts away from each other ?

JET951

Hi John C ( upfixenderporsche ) I just remembered , you may of forgotten like me , but on Landshark ( Australian 928 web site ) 24th December 2013 post number 126242 you posted that you have been using Penrite 15W-60 for some time now in your'e 928 , so no wonder you do have OK oil pressure at idle when engine hot on a hot day , you stopped using Delvac 5W - 40 well before our last summer

So with the UOA , make sure you mention that your'e 928 was on a 15w-60 Penrite & not a dedicated diesel oil , it saves a lot of confusion

UpFixenDerPorsche

Harrrrr --- I knew it !!!!

Like a bee to a honeypot - Jet951 - you couldn't resist the temptation could you? Hee hee.

Let's be up front Bruce (Bruce Buchanan - Jet951): you have never gotten over your stoush with Doug Hillary re his recomendation of Delvac 5W-40 (with 50,000k's of good UOA's) in the face of your addiction to 20W-50.

Nor could you get over my concurrence with Doug of my use of Delvac 5W-40 in my S4.

Itr didn't even matter that Doug put his money where his 'industrial excellence' mouth is for you to understand what he was saying to you.
(Just as well we have ppl like Doug with such scientific lubrication excellence as to share his knowledge with companies like Exxon-Mobil, Cummins etc).

So here we go again: you can quote, line and verse, my comments for the last 15 years: so where you think I've been inconsistent with my opinion.

Oh my heavens - what does that say about you?

And we haven't yet touched on the issue of a clogged oil cooler.

Re your beginning quote: yes - I had changed to Penrite 15W-50 Extra Ten until I had resolved an elevated temp. problem, based on the oil I had at hand, without remembering / considering stuff from ten years earlier (depression. family disasters and so on).

As it happened, the Extra Ten bit is all BS, with the 100C viscosity equalling that of 60W 100C viscosity: 25cS vs 18cS.

No wonder my OP was in meltdown on 40C days: heat being generated by pumping such thick oil ladded to severe loss of OP on 40C days.

Now - having cleaned / cleared oil cooler / my brain and changed back to Delvac - viola!!!

Why did I ever forsake you Oh my Delvac ???

My recollection of our last exchanges on Landshark centerd around the uselessness of an oil cooler in hot weather, despite me posting evidence to the contrary.

After that I resigned form Landshark on the basis that one could do very little in the face of determined ignorance, despite the obvious: blow air through a radiator and 'stuff' will be cooled.

Says much about science education standards in Oz.


Cheers Bruce.



Upfixen.

PS: So with the UOA , make sure you mention that your'e 928 was on a 15w-60 Penrite & not a dedicated diesel oil , it saves a lot of confusion

Yes Bruce.

JET951

Thats quite funny John ,but anyway using a 15w-60 oil is not a disgrace , you are the one who mentioned you have been using a 15w-60 " For quite some time " on Landshark , John there is nothing wrong with that , just please try not to say you are using something when you are not because that is deceitful

And as for resigning from Landshark , it was Len who told you to leave because of you're replies , so please get some of the facts straight

As for Doug Hillary , he never hung around long enough for me to have a discussion with , every time I asked him a question he just packed up & left as he did on Landshark & Rennlist , which is a shame because I liked exchanging Porsche oil related matters with Doug

UpFixenDerPorsche

Bruce - all I've got to say is that you're not in the faintest of leagues when it comes to understanding lubrication engineering on the same level as Doug., so don't for a moment pretend you and he are 'lubrication' mates in any sense of the word.

As for him 'packing up and leaving': why would he continue to waste his time attempting to help determinedly ignorant village idiots?

What could he possibly know that 'we' don't?

After all he has worked as a lubrication design engineer for next to all to the world's best automotive companies during the last 50 years.

When with Duckhams in the '60's he developed the industry's first 20W-50 oil.

His company keeps such high quality scientifically-based prime mover maintenance data that it interchanges data with companies such as Mobil and Cummins

Putting it it bluntly, Doug puts his money where his mouth is. and on a multi-million scale and succeeds.

Arrrrr gee Bruce - let it go will ya?

.

JET951

John , what on earth are you on about , I have spent 37 + years working on Porsche cars for a living ,Doug Hillary isn't even a motor mechanic let alone & Porsche trained one , I know what keeps last century Porsche's working reliably at high RPM , using a low viscosity primary diesel oil the Porsche & Mobil say not to in a petrol powered sports/Gt car engine does not sound that clever , it actually sounds quite weird to even recommend it , with all the last century Porsche engines destroyed at high RPM in the Australia heat by people using a 5w - 40 & then making the matter worse by recommending an oil that is high in detergents that foams way too much at high RPM is just plain reckless , if I put my name to that silly idea would be very stupid to say the least

If you have switched back to Delvac 5w-40 ( but it must of been very recent ) , then thats fine just keep the revs low as you normally do & I hope you go OK , by the way ,you never did say why you switched away from Delvac ( for quite some time ) did you have too low oil pressure hot issues ? , because you were very keen on the 15w-60 Penrite & the good levels of ZDDP it has , because for you to even think of using a 15w anything , there must of been a oil pressure issue

Keep Well
Bruce

Brett928S2

Hi Bruce

I dont understand the politics of the last few posts and dont care either...lol

But I do KNOW you are correct about high revs and wrong spec oil....

I had my rev limiter removed by John Speake so that my car in THEORY would rev to 9700 ....and with my Nitrous system I regularly take it well past 8000 (even if only for short bursts)

During the process of gradually increasing the amount of Nitrous from 100hp to 2000 I started on a 0/40 and worked up from there in stages to my current 15/50 Ester Full synthetic...

The reason I started changing oil grades was LACK OF OIL PRESSURE...particularly at high revs....

I suspect I was lucky that I didnt blow the rods/crank to be honest...as i was on the very edge of what they would put up with...as an Ex Race mechanic I knew that if I didnt increase the oil pressure , I would lose an engine....so each time i increased the oil grade and tried again at high revs, not forgetting that no other 928 can (or should) rev to over 8000...

So, yes you are absolutely spot on....

All the best Brett

Ad0911

My contribution may be a bit but some years ago I heard that camshafts and cam followers of 930 engines could be ceramic coated. Could this be a possible solution to the 928's flat cam follower problem?

hacker-pschorr

I respect Doug's research and testing, and even followed in his footsteps with my 81. On a July day my oil pressure fell to zero at idle, the warning light came on and my lifters sounded like they were going to leave the engine. As soon as I got home, I switched to 15w-50 and haven't had a problem since.

I was not the only 928 owner who experimented with this based on Doug's findings who had similar results. Andrew Olson also had a bad experience testing 5w-40 Rotella in his GT.

I don't need to be an oil expert to know my 928 does not like 5w-40 Delvac.

marine928

see #2 and check out the website in post # 7. Its all about composition. The Lubriguard is low foam as well. Made trip to SITM this year (2117 miles r/t with detours) Everyone is doing 80 plus mph. Really put the oil to the test, no issues. My running pressure is 5, idle around 2.5-3.0. Engine temps always at 1st bar or slightly above it. ( a/c, hot Houston, Tx. weather.)
Immediate starts, engine smooth as a sewing machine ( German of course). For racing probably not good, but compare the testing specs and viscosity index on the web site and let me know what you think.

Alan

Sounds like you are running too cool...

Alan

Don Carter

Jim,

Very interesting information. I wonder where the Pure Plus Platinum fits in since it's base oil is derived from natural gas. Group V, or maybe this information is now out of date and a new Group is needed?

Tazzieman

Porsche have recently put a $$$ "classic" oil on the market for 911 owners. Most of us realise this is a marketing ploy.
No doubt they will soon cater for poor 928/944 owners who don't possess or can't read the owner's manual .
And no doubt , this German "Voila!" (not "viola" or "wala") will suck the punters in.