Notices
928 Forum
Sponsored by:
Sponsored by: 928 Specialists

Oil additive for high mileage 89 S4?

 
Old 01-26-2019, 12:51 AM
  #16  
928 at last
Addict
Rennlist Member
 
928 at last's Avatar
 
Join Date: Jul 2008
Location: Aurora, Ontario, Canada
Posts: 2,157
Talking What Hacker said.....

Originally Posted by Hacker-Pschorr View Post
No. It's a waste of money and could actually upset the additive package in the oil you are using.

Additives are a complete package. Think of is like baking cake, just pouring in more of any of the ingredients just because you like it doesn't necessarily make the cake better and could upset the balance of the other ingredients.

Long story short, prior to about the year 2000, every oil has about 1100 / 1200 ppm of ZDDP. Thanks to the EPA that number was dropped to 600 / 800 (something about damaging catalytic converter which may not actually be true at all)

The collector car world reacted, and most thicker oils (like 15/20w-50) went back to the old formula, life was good. Almost no cars made in the last 10 years use anything thicker than 40wt (most are 30 or even 20) so the oil companies were able to keep producing the oil's classic cars need without upsetting the tree huggers involved with new car regulations.

Bottom line, buy an oil with the "old" standard 1100 / 1200 ppm ZDDP and the correct viscosity for your climate. 161k miles is not high for a 928.

Thankfully there are very 15/20w-50 oils on the market with the lower level of ZDDP.

Valvoline VR-1 (regular or synthetic)
Motule
Brad-Penn
Redline
Royal Purple
Just to name a few.


Define "often" - the mileage most of these cars are driven, annually is sufficient.
I've used Brad Penn Racing "The Green Oil" for a decade and thousands of miles. ZDDP where we need it and no issues. Changed once per year.
Likely a bit more expensive than the WalMart alternatives, but no-one ever said maintaining a Porsche was a WalMart level financial commitment.....
928 at last is online now  
Old 01-26-2019, 03:56 AM
  #17  
FredR
Addict
Rennlist Member
 
FredR's Avatar
 
Join Date: Jun 2005
Location: Oman
Posts: 5,693
Default

Originally Posted by jschiller View Post
I will be doing my first oil change soon on my recent purchase and the oil cooler thread currently running set me to thinking.

Fred mentioned that he uses STP in his engine in a really hot environment. My ambient temps don't reach Fred's levels but I do have 161k on the motor that seems never to have been apart.

So my question is whether I can benefit from adding any ZDDP additive, and if so, what is the consensus on which one?.

I do p[an on sending a sample to Blackstone for analysis. I will be using Mobil1 15W50 which is supposed to be high zinc anyway.. Thoughts on an additive, or not?
John
John,

My circumstances are somewhat different to you folks in that I have very limited choices when it comes to lube oil selection. 20 years ago when I purchased my late S4 I ran with a Castrol synthetic lube that had a viscosity rating of 10w60. That mysteriously disappeared off the local market and then I managed to get Redline 20W50 from Dubai for a few years and then that source "disappeared". I then lost my S4 in a big smash and a year or so later "the phoenix rose from the ashes" with the motor transplanted into my current GTS chassis that now has some 95k miles under its belt. The motor was solid, we removed the heads, lapped the valves and resealed the motor. This was done as "a project" by the local agents at a very reasonable price. When the car was ready I took for it for a test drive, the motor felt great but this was during the hot season and after the motor was fully warmed up I noticed the oil pressure at idle was something like 1 barg and that scared the poo out of me. I drove the thing back to the dealers knowing whereas Mobil 1 had been used, I had not checked what viscosity was used. upon return to base I was advised they had filled with 0W40 and my brain flipped. To be fair, the agents told me they had checked with their heirarchy and that this oil was suitable for use in the 928. I politely said "no way" and tried to find a suitable brew. The best option I could find at the time was Castrol GTX. A year later, next oil change I could not even find that. After some research I decided to fall back on Shell Helix Super that is a API SL brew. This supposedly should be suitable for engines of our period and earlier API specs are just not available.

I then started doing some research that suggested STP oil treatment was a good source of ZDDP and more to the point, could add a little to the viscosity index and this help the oil pressure at idle a little. The lowest temperature my motor ever sees is about 17C so no cold starts. The oil pressure is generally solid at 2 barg on most hot days and on one occasion when I took it out on a "scorcher" it dropped a little below the 2 barg mark. I floated this approach on the list for opinions and got a reply from the Buchanan boys down under who told me they did exactly the same thing on the 928's they look after and that was good enough for me.

Given the choices you have such approach is not really necessary and mileage covered was never a concern in my case ad probably should not be in your case as the alusil bores seem to swallow such miles effortlessly unless premature damage of some kind has been done to the motor and then you would have much greater issues to deal with- hopefully not the case.

The STP treatment has been around longer than me and I first used that stuff in my ancient technology British motorcycle engines back in the days when lube oils were not as advanced as they are today. That the stuff is still marketed and widely available suggests that its use is not likely to do any damage or they would have been dragged through your courts long since. If I had your choice of available lubricants most likely I would not take this approach but as I can tell it seems to work fine. Last time I had the cam covers off a couple of years ago the cam lobes looked perfect and so is my oil pressure.

Trust the above of interest.
FredR is online now  
Old 01-26-2019, 10:12 AM
  #18  
SwayBar
Addict
Rennlist Member
 
SwayBar's Avatar
 
Join Date: Feb 2006
Location: Chicago Bears
Posts: 2,313
Default

There is no need for an additive if one uses a quality oil, and there are plenty of them.

Do a Google search, and you'll find that's what the industry oil-guys say.

Along those lines you'll also find that adding additional ZDDP is counter productive. Just because other's have done it with no readily-apparent issues doesn't make it a good practice.

The same can be said for using a race-oil in a street engine. It may sound cool to your buddies that you're using a 'race oil' in your Porsche, but the reality is that's the last oil you'd want to run in a street car.

Don't over-think it and just use any good street-oil and be done with it.
SwayBar is online now  
Old 01-26-2019, 10:23 AM
  #19  
andy-gts
Addict
Rennlist Member
 
andy-gts's Avatar
 
Join Date: Aug 2006
Location: lawrence,kansas
Posts: 2,082
Default

I use 20-50 wt with 1300+ on both zinc and phos, AMSOIL Z ROD 20-50 been very happy
andy-gts is offline  
Old 01-26-2019, 01:45 PM
  #20  
jschiller
Addict
Rennlist Member
Thread Starter
 
jschiller's Avatar
 
Join Date: Feb 2010
Location: Cape Coral, FL
Posts: 95
Default

Originally Posted by FredR View Post
John,

20 years ago when I purchased my late S4 I ran with a Castrol synthetic lube that had a viscosity rating of 10w60. That mysteriously disappeared off the local market and then I managed to get Redline 20W50 from Dubai for a few years and then that source "disappeared".

Trust the above of interest.
Yes Fred, very interesting. I presently use Castrol TWS 10W60 in my M5 which is priced about the same as "race oil" (ca, $15/qt). Do you think that is a better choice than the Mobile1 15W50? I'm not trying to reopen the "Which oil to use" debate again, just wondering if the greater viscosity range would be of any use here in Florida where it never freezes or gets much above 100 F.
jschiller is offline  
Old 01-26-2019, 02:36 PM
  #21  
FredR
Addict
Rennlist Member
 
FredR's Avatar
 
Join Date: Jun 2005
Location: Oman
Posts: 5,693
Default

Originally Posted by jschiller View Post
Yes Fred, very interesting. I presently use Castrol TWS 10W60 in my M5 which is priced about the same as "race oil" (ca, $15/qt). Do you think that is a better choice than the Mobile1 15W50? I'm not trying to reopen the "Which oil to use" debate again, just wondering if the greater viscosity range would be of any use here in Florida where it never freezes or gets much above 100 F.
John,

Had it been available for me to use I would not have hesitated to use the Mobil 1 15W50 variant providing the ZDDP content was adequate as that is essential for the flat bucket tappet configuration in our engines. I doubt there is a specific need for you to use that Castrol variant but I would think it should also be fine. I seem to remember BMW specified nothing but the Castrol lube for your M5 [very nice engine/car that model series]. Basically you are spoilt for choice and doubtless you have some excellent recommendations in this thread. I was very happy with both the Castrol and the Redline when I could get them.
FredR is online now  
Old 01-26-2019, 04:16 PM
  #22  
GregBBRD

Rennlist
Basic Site Sponsor

 
GregBBRD's Avatar
 
Join Date: Feb 2005
Location: Anaheim
Posts: 9,543
Default

Unless you have a specific reason to use an "engine cleaner" (lifter noise), just use the proper viscosity oil (15-50 or 20-50 unless you live in a very cold climate), with ZDDP over 1100 ppm.

If you have lifter noise...which is generally caused by deposits (black junk) on the check ball seat of the lifter, Swebco 502 is a good "solvent" and seems to work very well (I have no experience with Rislone or any other additives....I never had to find something that works better than Swebco.)

Any engine "cleaner" is going to "rinse" loose gunk.....that's why it is used. If you have an old engine with high mileage and you use a cleaner, I'd suggest changing the oil and filter soon (250 miles, maximum), after using any product like Swebco.

Lifters have internal "sludge" shelves. Crankshafts have blind oil passages that are "sludge traps." Cylinder heads have blind drillings that collect sludge. Loosening the sludge in these areas will put that sludge into suspension (and in the case of the crankshaft "sludge traps" run the thick, hardened, gunk directly to the rod bearings), which can damage the bearings.

How much "gunk" collects in our engines?

I disassembled a GTS engine with just over 100, 000 miles (which had TERRIBLE looking rod bearings), a couple of weeks ago, and tried to see if I could clean out the "sludge traps" without removing the "plugs". (I do this, commonly.) Huge "wads" of black gunk came out...1/4" x 1/4" "chunks" of hardened, abrasive, metal ladened, carbon-like material. After an hour of fussing with the crank, I still did not have two "throws" (much less the other six) clean and gave up. Off to the crankshaft shop, for removal, drilling, and tapping of the galley plugs, so the blind holes could be cleaned.

Would an engine cleaner have hurt this engine, before it was taken apart? I've got no idea, but I do know the only path that gunk can go, if loosened....straight to the rod bearings!

In short, only use an "additive" if you have a specific need....don't "toss" in additives for the shear "what could it hurt" sake. Think about what you are trying to accomplish and what ramifications your action might have.

If all you need is an oil change....change the oil.


Last edited by GregBBRD; 01-26-2019 at 07:54 PM.
GregBBRD is offline  
Old 01-26-2019, 06:34 PM
  #23  
jschiller
Addict
Rennlist Member
Thread Starter
 
jschiller's Avatar
 
Join Date: Feb 2010
Location: Cape Coral, FL
Posts: 95
Default

Originally Posted by GregBBRD View Post

If all you need is an oil change....change the oil.
Sounds like sound advice. I think that's the approach I'm going to take.
jschiller is offline  
 


Thread Tools
Search this Thread

Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: