Andre The Giant

I was depressed to see the oil which I was using in my baby was not rated very well, NOT at ALL. I was using the Royal Purple HPS Synthetic 20w50. Now considering moving to the Valvoline VR1. The bonus is that this oil is half the price of the other !

http://www.motoroiltests.com/car-oil...l#.WIeTSlMrIUE

jtrygstad

Interesting to see that Mobil 1 15W50 came in low at number 42 on list (based on psi).

hb253

Looks like this is the source site: https://540ratblog.wordpress.com/

Lots of reading, but a CTRL-F will help you find the ranking.

Hugo

bureau13

I've been using the RP oil as well, but I could have sworn there was a test somewhere that had it ranking quite highly. Hmm...

Imo000

Is that site credible or is it "Fake News"?

Jfrahm

It's interesting how much MOS2 is in some of these oils, I have wondered about it as a defense against thrust bearing wear. There are some additives, Liqui Moly, Schaeffers #132...

I think some have suggested it might help reduce cam chain tensioner/guide wear also.

hb253

It's alternative facts

I believe the link I ppsted is the original source., If you scroll to the bottom of motoroiltests.com, you see a statement crediting "540 rat".

Hugo

ptuomov

My understanding is that 540 Rat's test is for a thin film condition. Maybe most applicable to cam-lifter interface in our engines?

In thick film condition, other things matter.

Yet another question is how likely are different oils in thin film vs. thick film condition. I think (but don't know) that viscosity is the main determinant whether the bearing is in thin film vs. think film condition, high viscosity oil more likely resulting in thick film condition.

Want to be

Surprised about the Lucas oil.

Why is it not suitable for street use? Too much zinc? Can I use this without harming my car?
I drive about 600 miles a year.

I'd buy the 20/50 blend.

Looks better than Brad Penn

2. 10W30 Lucas Racing Only = 106,505 psi
zinc = 2642 ppm
phos = 3489 ppm
moly = 1764 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

Mikebte

Not sure this is a credible source. But always fun to read others thinking.

I am a strong believer in running what your engine likes.
I have a friend who has the same engine as me. I run Castrol. He ran Castrol and used a Qt of oil. He switched oils and now has no issues. Both engines around 114K.

Run what your engine likes.

jcorenman

Phil, 2642 zinc is crazy high, most recommendations are less than half that. And some of the top-rated oils on that list are in the 600 range, that's not right either. But whatever the numbers, don't ever assume the composition for a 10w30 is going to translate to a 20w50.

There are plenty of oil threads here, do some reading and if you want to stray far from what others are doing then send a sample off for testing. As for this site, interesting info but there is disagreement on the innerwebz about the methods: do a google search for "rat540", the author's usual handle.

worf928

You have to go very far down that list to find a 50w oil with a goldilox-level of zinc and phosphorus.

Andre The Giant

Thank you all for your comments. I was also wondering how valid is this since this is only one website and you can't always believe everything on the interweb ! lol
What would be great to have would be the original recommendations from Porsche with the amount of zinc, phosphor and moly required at a minimum for our flat tappet engines.

And yes oil conversations on this forum is like opening a can of worms ! lol
I found this article interesting to say the least. I might decide to call Porsche to see what specs the oil should be. I had also checked the owners manual, but it only recommends oil types, but those were mainly for the 80's !

More research is at hand.

Andre The Giant

Look at his, I was not aware !
I found this on the original blog which was posted by another person.
https://540ratblog.wordpress.com/

172. “ZDDPlus” added to Royal Purple 20W50, API SN, synthetic = 63,595 psi
zinc = 2436 ppm (up 1848 ppm)
phos = 2053 ppm (up 1356 ppm)
moly = 2 ppm (up 2 ppm)
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 24% LOWER than this oil had BEFORE the ZDDPlus was added to it. Most major Oil Companies say to NEVER add anything to their oils, because adding anything will upset the carefully balanced additive package, and ruin the oil’s chemical composition. And that is precisely what we see here. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised.

ptuomov

Please keep us updated based on what you find.

My research has lead me to believe in the following. These are beliefs, not facts!

First, viscosity. The original Porsche viscosity recommendations are probably good for a stock engine, given that the viscosity standards have not changed (for the worse) since then. If the engine is modified to make more torque, then I think one should increase the viscosity somewhat. I think the hot viscosity is the most important oil selection criterion, because it determines whether bearing surfaces are in the thick film or thin film lubrication regime. Higher viscosity may require additional / better oil cooler(s), though.

Second, the measured protection ability such as that measured by 540 Rat is relevant for situations where the surfaces are in thin film regime. I believe that his measurements are as valid as or more valid than what is available anywhere else, provided that they are used correctly. Using them incorrectly, for example, as a substitute for viscosity selection would be a mistake -- but it's not 540 Rat's mistake, it's the user's mistake.

Third, most current oils have more advanced substitutes for zinc dialkyldithiophosphate aka ZDDP. Therefore, on the one hand, one can't say that oil is not good for flat tappets if it doesn't have certain amount of ZDDP. But on the other hand, one can't really say it's good either! Therefore, I think that if the oil does have a certain amount of ZDDP, such as above 800 ppm, then the downside is that the oil probably doesn't have the latest high-tech anti-wear agents but the upside is that at least it has enough of the old-fashioned anti-wear agents. So with ZDDP over, say, 800 ppm I am thinking that you are unlikely to get the absolute best wear protection, but you're probably going to get _good enough_ wear protection.

Then there's the paranoid part of me who thinks that some smaller oil companies, not Exxon Mobiles of the world but the hot-rodder outfits, are adding so much ZDDP to their oils for purely marketing reasons that they actually make oils much worse. They can corner a market niche this way, because Exxon Mobile is not going to add stupid and harmful amounts of ZDDP to the oil to cater this small market segment. And every time some hobbyist posts about ZDDP on the internet, the "minimum" required ZDDP seems to go up, reinforcing the marketing-related excess ZDDP spiral.

Just to be clear, these are beliefs, not facts.