| Author |
Message |
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52718
|
 Posted: Sun Dec 07, 2025 11:16 pm Post subject: Re: Official "What oil / additives should I use" topic |
 |
|
| HandOverFist wrote: |
You won't find a conclusive recommended ppm of ZDDP simply because it does not exist and for good reason. The amount of ZDDP in any oil has nothing to do with added protection because the compound simply does not operate in that fashion. In other words, greater ZDDP content does not offer greater protection...it merely extends the depletion time. 800 ppm of ZDDP works exactly the same as 1200 ppm of ZDDP. If one ever takes the time to review used oil samples you will discover the depletion rates of ZDDP are rather miniscule...as it should be. The compound is just along for the ride inside oil doing nothing until it is called upon/activated by extreme heat/pressures. If you ever discover a serious depletion of ZDDP in your oil you have a serious problem with your engine and it is not long for this world no matter how much ZDDP you throw at it lol. |
The ZDDP in oils 25 years ago tended to be "consumed" by the engine and would end up coating the cat causing it to die an early death. Since then the producers of motor oil have gone to better refined ZDDP molecules which don't evaporate from the oil or degrade as readily, so less ZDDP is needed to provide long term protection.
25 years ago it was probably not too bad of an idea to increase your oil's ZDDP from 800 ppm to 1000 or 1200 PPM, however I wouldn't expect more than one in a hundred people to be able to do the math to know how much to add of a given ZDDP concentrate while one of the frequently recommend ZDDP boosters had so little ZDDP that adding any amount of it would lower the concentration of ZDDP in most anyone's crankcase. |
|
| Back to top |
|
 |
HandOverFist
Samba Member
Joined: November 14, 2025
Posts: 7
Location: FL
|
| Posted: Sun Dec 07, 2025 9:05 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| vamram wrote: |
Not sure if this has been posted somewhere in this monster thread, but the guys goes thru a bunch of oil additives he says destroy engines. He's really down on the zddp additives and Marvel Mystery Oil, among others.
Link
|
540Rat https://540ratblog.wordpress.com/2013/06/20/motor-oil-wear-test-ranking/ documented these findings long ago. He found (specifically ZDDP type additives) that the introduction of these aftermarket additives to any established oil package resulted in a drastic reduction of that oil's protective qualities in nearly every oil he tested.
There was one additive (which will not be named) that actually improved the oil's protective qualities, but...this improvement did not hold true with every oil. The additive was also very corrosive and not recommended overall.
I find the ZDDP debate wearisome at best. Today's off the shelf oils average around 800 ppm of ZDDP. It just so happens that the same oils from 1960-1970 had the exact same ppm levels of ZDDP as today and this was during the heyday of high performance flat tappet engines coming from auto manufacturers. Prior to 1960 these levels were even lower...by a lot.
You won't find a conclusive recommended ppm of ZDDP simply because it does not exist and for good reason. The amount of ZDDP in any oil has nothing to do with added protection because the compound simply does not operate in that fashion. In other words, greater ZDDP content does not offer greater protection...it merely extends the depletion time. 800 ppm of ZDDP works exactly the same as 1200 ppm of ZDDP. If one ever takes the time to review used oil samples you will discover the depletion rates of ZDDP are rather miniscule...as it should be. The compound is just along for the ride inside oil doing nothing until it is called upon/activated by extreme heat/pressures. If you ever discover a serious depletion of ZDDP in your oil you have a serious problem with your engine and it is not long for this world no matter how much ZDDP you throw at it lol. |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52718
|
| Posted: Tue Sep 16, 2025 6:51 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| boburban wrote: |
I called Shell customer support and talked to one of their technical folks.
He told me that Shell Rotella T1 has 1100 ppm of Zinc. Shell Rotella T4 and above has 1200 ppm of Zinc.
Hope that helps as I could not find a definitive answer online. |
What phone number did you use for their customer support? Rotella T6 5w40 was one of my chosen oils for years when it carried an "S" rating. If not having an "S" rating just means it is going to harm a catalytic converter without doing other harm, I would like to know as none of my aircooled engines have cats. |
|
| Back to top |
|
|
vamram 
Samba Member
Joined: March 08, 2012
Posts: 8232
Location: NOVA
|
| Posted: Tue Sep 16, 2025 3:44 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
Not sure if this has been posted somewhere in this monster thread, but the guys goes thru a bunch of oil additives he says destroy engines. He's really down on the zddp additives and Marvel Mystery Oil, among others.
Link
_________________
"Men are qualified for civil liberty in exact proportion to their disposition
to put moral chains upon their own appetites. -Edmund Burke
'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...we hardly knew ye. Sold 2025 for peanuts.
Click to view image
Save the Supers!! |
|
| Back to top |
|
|
vugbug68
Samba Member
Joined: June 25, 2006
Posts: 2701
Location: sacramento
|
| Posted: Tue Aug 26, 2025 6:22 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| boburban wrote: |
I called Shell customer support and talked to one of their technical folks.
He told me that Shell Rotella T1 has 1100 ppm of Zinc. Shell Rotella T4 and above has 1200 ppm of Zinc.
Hope that helps as I could not find a definitive answer online. |
I'm sure someone will chime in and say diesel oil shouldn't be used in gasoline engines, but those ZDDP levels in Rotella look about the same as an oil analysis chart I posted in this thread 10 years ago. As far as the anti-foam agents, I can definitely understand not using it in a engine thats gonna be spinning high rpm.
Anyway I've been using Rotella 15-40 and 10-30 in my VW's for 20 years, I've used VR1 10-40 too with similar results, Rotella is just easier for me to get and is cheaper.
_________________
71 Super
66 Corvair
69 Baja Bug |
|
| Back to top |
|
|
boburban
Samba Member
Joined: July 28, 2025
Posts: 2
Location: Cleveland, Ohio, USA
|
| Posted: Wed Jul 30, 2025 8:13 am Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| DesertSasquatchXploration wrote: |
| I cant believe AutoZone and O'Reilly here only carry 60W VR-1. I asked the counter and they thought I was speaking a different language asking for 10w-30 or 20w-50. I used to buy it from them only a year ago. Force me to go online yet they wonder why stores are empty. Screw'em |
My Wal-Mart has 5 quart jugs of VR1 10W-30 and 20W-50 for about $5 per quart which is a really good price. |
|
| Back to top |
|
|
boburban
Samba Member
Joined: July 28, 2025
Posts: 2
Location: Cleveland, Ohio, USA
|
| Posted: Mon Jul 28, 2025 9:06 am Post subject: Re: Official "What oil / additives should I use" topic |
|
|
I called Shell customer support and talked to one of their technical folks.
He told me that Shell Rotella T1 has 1100 ppm of Zinc. Shell Rotella T4 and above has 1200 ppm of Zinc.
Hope that helps as I could not find a definitive answer online. |
|
| Back to top |
|
|
DesertSasquatchXploration
Samba Member
Joined: April 16, 2021
Posts: 1060
|
| Posted: Sat Jun 21, 2025 10:07 am Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| oprn wrote: |
I don't know if it has been covered here yet or not but for all you heavier is better folks I am seeing ads now for 60wt "racing" oil.
Not my cup of tea but some may want to try it. It's gotta' make your car faster... no? |
I cant believe AutoZone and O'Reilly here only carry 60W VR-1. I asked the counter and they thought I was speaking a different language asking for 10w-30 or 20w-50. I used to buy it from them only a year ago. Force me to go online yet they wonder why stores are empty. Screw'em |
|
| Back to top |
|
|
modok
Samba Member
Joined: October 30, 2009
Posts: 27754
Location: Colorado Springs
|
|
| Back to top |
|
|
jim martin
Samba Member
Joined: January 14, 2004
Posts: 399
Location: Vancouver, BC
|
| Posted: Fri Jun 20, 2025 2:54 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
just chucking it out there, just a different way to look at it and save time with the guessing game.
doesn't anyone measure clearances anymore ?
its kinda the first step in picking a oil weight .
then run it and monitor pressure .
for example my last motor ran main clearance of 0.005" .that motor ran 20w-50
on yearly inspection all bearings looked as new .pressure was ok .
new motor mains are 0.0027" ,will due the same fire it up on 30w and check oil pressure when oil is 200 deg .and in theory will drop down to 10w-40 and again run it an check , simple .
if you don't know your clearances , fire it cold get your idle and driving pressures cold . watch pressures during warm up then when its real hot .
recheck those idle. and say 3500-4000 rpm pressure .you will know if you need to go up or down on your oil weight choice.
knowledge is power .
and you want to save fuel run a 0w-20 . 
bearing Oil Clearance Chart for reference
https://cdn.shopify.com/s/files/1/0827/6783/9538/f...1697433294
_________________
B.C's fastest street legal vw , June 2006 Hot VW's feature car 9.81 sec at 145.26mph.
Sponsored by :
LUCAS OIL PRODUCTS http://www.lucasoil.com
KROC head porting services
Dialedinperformance.com
Airspeedparts.com topic http://airspeedparts.com/forums/index.php?topic=914.0 |
|
| Back to top |
|
|
Bruce
Samba Member
Joined: May 16, 2003
Posts: 17675
Location: Left coast, Canada
|
| Posted: Tue Jun 10, 2025 3:05 am Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| oprn wrote: |
I don't know if it has been covered here yet or not but for all you heavier is better folks I am seeing ads now for 60wt "racing" oil.
Not my cup of tea but some may want to try it. It's gotta' make your car faster... no? |
In Mexico, it's pretty easy to find 25W-60 engine oil. The numbers are bigger, so it's gotta be better, right?
_________________
| overheard at the portland Swap Meet... wrote: |
| ..... a steering wheel made from a mastadon tusk..... |
|
|
| Back to top |
|
|
modok
Samba Member
Joined: October 30, 2009
Posts: 27754
Location: Colorado Springs
|
| Posted: Sat Jun 07, 2025 2:33 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
Finest crash course on the subject I've ever seen.
Welcome to the future, it's not so bad
And mobil one classic looks pretty legit
https://www.youtube.com/watch?v=a3uXSI9wQv8 |
|
| Back to top |
|
|
oprn
Samba Member
Joined: November 13, 2016
Posts: 15223
Location: Western Canada
|
| Posted: Fri May 23, 2025 12:39 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
I don't know if it has been covered here yet or not but for all you heavier is better folks I am seeing ads now for 60wt "racing" oil.
Not my cup of tea but some may want to try it. It's gotta' make your car faster... no?
_________________
Our cars get old, we get old but driving an old VW never gets old! |
|
| Back to top |
|
|
vamram
Samba Member
Joined: March 08, 2012
Posts: 8232
Location: NOVA
|
| Posted: Tue Apr 22, 2025 1:26 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| Glenn wrote: |
If your engine is high mileage i'd use a 10W-40. If relatively new, i'd use a 5W-30.
|
Synthetic or dino...?
_________________
"Men are qualified for civil liberty in exact proportion to their disposition
to put moral chains upon their own appetites. -Edmund Burke
'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...we hardly knew ye. Sold 2025 for peanuts.
Click to view image
Save the Supers!! |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52718
|
| Posted: Sat Feb 08, 2025 10:29 am Post subject: Re: Official "What oil / additives should I use" topic |
|
|
If one runs a 50wt oil the engine will require more oil pressure to get the same volume of oil through the galleys and to the bearings than if you run a thinner oil, while if you have a stock oil pressure relief set up you will ALSO be bypassing the cooler and potentially dumping more oil back to the sump if you make too much pressure, so the actually oil volume to the bearings can be reduced significantly with a thicker oil. Measuring oil pressure just doesn't tell the entire story, VW gives a spec for oil pressure for 30wt oil, so if you were wanting to run a 50wt you would have to have a higher pressure to get it the same amount of oil to the bearing, which might well mean the VW oil pressure relief/cooling system is going to let the oil bypass the cooler and get hotter.
I remember decades ago plugging in the numbers for all the variables of the lubrication system on a then new engine using an accepted engineering equation and coming up with 30wt as the oil that would give the best all around results as far as journal bearing life. I doubt if much has changed since.
I you have loose bearing clearances then you may need a thicker oil to make up for the slop. |
|
| Back to top |
|
|
Bruce
Samba Member
Joined: May 16, 2003
Posts: 17675
Location: Left coast, Canada
|
| Posted: Sat Feb 08, 2025 9:34 am Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| the video wrote: |
| " if your engine turns 10,000 rpm, you need 100psi oil pressure. |
_________________
| overheard at the portland Swap Meet... wrote: |
| ..... a steering wheel made from a mastadon tusk..... |
|
|
| Back to top |
|
|
vamram
Samba Member
Joined: March 08, 2012
Posts: 8232
Location: NOVA
|
| Posted: Thu Feb 06, 2025 6:12 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
Hmm...can't wait to see the comments. I'm no expert. I use QS full synthetic 5w/30 Dextros 1 on my year-round daily driver '73 1600dp in all temps, nothing fancy. I've *never* had pressure or oil temp problems on this car.
[Edit: Pet-peave: why do so many youtubers always fly their hands around the screen so it becomes the main focus of the video???  ]
_________________
"Men are qualified for civil liberty in exact proportion to their disposition
to put moral chains upon their own appetites. -Edmund Burke
'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...we hardly knew ye. Sold 2025 for peanuts.
Click to view image
Save the Supers!! |
|
| Back to top |
|
|
hobthebob
Samba Member
Joined: December 08, 2021
Posts: 482
Location: Austin, TX
|
| Posted: Thu Feb 06, 2025 4:47 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
Sorry! I posted this in another thread, but I wanted to know what you guys think of this guy and his video on oil?
Link
|
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 52718
|
| Posted: Fri Jan 31, 2025 2:36 pm Post subject: Re: Official "What oil / additives should I use" topic |
|
|
| bnam wrote: |
I’m newly reading this thread so forgive me if this question has been asked and answered before,
In an engine with a well regulated cooling system, the engine temperature remains the same (+/- 10F) whether it is 70F outside or 90F or 110F. So, why is there a need for hotter grade (say xW50) oil? Engine temp is anyway much greater than ambient. I’ve read that engines are typically designed to need about 10 centistokes at operating temp (100c/212F). xW30 and xW40 would seem to more than meet that need.
Thx,
Byas |
There is a reason why for decades 10w30 was the best selling oil around the world and if an engine called for a single weight oil it was typically 30wt.
VW recommended against multigrades and recommended fairly thin straight weight oils like 20wt for moderate temperatures and 30wt for hotter temperatures for a long time, and then for a couple of year did recommend multigrades for cooler temps only, but dropped that recommendation again and went back to only recommending straight weight oils, I think they started recommending 40wt at the highest tropical temperatures at that time. After another four'ish years they put multigrades back on the chart. Personally I am glad I had already learned a lesson on running needlessly thick oil on another rig and on the first VW I did regular maintenance on (a 1966 Beetle) ran the recommended 30wt in the summer. Not running super thick oils has served me very well over the years, as more oil passes through the cooler and less gets dumped right back to the sump without being able to help cool anything. Unless one's engine is just built loose or badly worn, I don't think one is apt to get any real advantage from running an overly thick oil. |
|
| Back to top |
|
|
bnam
Samba Member
Joined: July 02, 2006
Posts: 3544
Location: El Dorado Hills CA/ Bangalore, India
|
| Posted: Fri Jan 31, 2025 9:32 am Post subject: Re: Official "What oil / additives should I use" topic |
|
|
I’m newly reading this thread so forgive me if this question has been asked and answered before,
In an engine with a well regulated cooling system, the engine temperature remains the same (+/- 10F) whether it is 70F outside or 90F or 110F. So, why is there a need for hotter grade (say xW50) oil? Engine temp is anyway much greater than ambient. I’ve read that engines are typically designed to need about 10 centistokes at operating temp (100c/212F). xW30 and xW40 would seem to more than meet that need.
Thx,
Byas
_________________
1971 1302LS Convertible (RHD) owned since '74
Click to view image
1965 Karmann Ghia Coupe - under restoration
1966 Fiat 1500 Cabrio (with 1600 Twin cam)
1952 Citroen TA 11BL |
|
| Back to top |
|
|
|
