Ultimate Motor Oil Thread or Why we hate CJ4/SM oils

[HarryD]

Jimmy,

Thanks for the update. One question, will the labelling on the front of the bottle help us make the right choice or will we need to delve into the fine print.

[cnavarro]

Originally Posted by Jimmysidecarr

Good afternoon.

I just wanted to pass on some information related to this thread topic since we (Royal Purple) recently reformulated our SAE/API street oils and although both old and new formula are still often able to be found, a little checking of the back label for the API license will be worth doing.

Due to the reduction in anti wear from the API-SM cap of 800ppm phosphorus our SAE/API-SM and SN street oils are no longer the best choice for flat tappet performance engines with lifts above .500". We do not recommend our SAE/API-SN 20W-50 (part #01250, quart bottle) or SAE/API-SN 10W-40 (part #01140, quart bottle) for those applications any longer.

There are still multiple Royal Purple oils available that are appropriate and though exact levels are proprietary, typical zinc and phosphorus are in excess of 1200ppm.

Those appropriate and recommended oils for air cooled Porsche engines are as follows.
If you can still find the old formula Royal Purple API-SL SAE 10w-40 and API-SJ 20W-50 those are fine and though they are not your best choice they will still be better than many other oils on the shelves these days.

As you go down the list the level of performance and protection increases and the price will too.

Royal Purple HPS 10W-40 (part #31140, quart bottle)(new)
Royal Purple HPS 20W-50 (part #31250, quart bottle)(new)

Royal Purple Max Cycle 10W-40 (part #01315, quart bottle)(unchanged)
Royal Purple Max Cycle 20W-50 (part #01315, quart bottle)(unchanged)

Royal Purple XPR 10W-40 (part #01041, quart bottle)(unchanged)
Royal Purple XPR 20W-50 (part #01051, quart bottle)(unchanged)

If you have any questions please feel free to contact me at the Royal Purple technical support department 8-5 mon-fri @ 888-382-6300

or via email : jmorrissey@royalpurple.com
or the general tech department email: rpautotech@royalpurple.com

Thank you for allowing me to share this important update.

Jim Morrissey
Technical Services
Royal Purple, Inc.

Yet another reason to safely say that motorcycle oils are a good backup choice with the usual suspects (Brad Penn, Swepco, etc.) are not readily available.

[mystro]

The RP XPR 10w40 is my first choice in oil.

[911pcars]

Goes to show that oils can be reformulated at will. What is contained last week can be added or removed the following week.

Sherwood

[timchar]

Is it true that Brad Penn is not to be used on cars with catalytic converters? Tim

[Reiver]

Originally Posted by timchar

Is it true that Brad Penn is not to be used on cars with catalytic converters? Tim

Higher zddp that protects flat tap motors, like our air cooled P's, has a neg effect (can plug up) cats...that is why it was removed or lowered in most 'modern' oils and why we are having this whole discussion.
I don't know if the P's cat is adversely affected by it or what the time line may be. I've removed mine so no idea.

[dshepp806]

Originally Posted by richardlw

All books, manuals, etc. need to be read in relation to what was known and available at the time of printing. I once worked for a company that tried to solve that problem. Every 6 months we sent out thousands of little stickers to registered owners with instructions as to which page to paste the corrections. On field visits I saw about 30% were applied.

Before good synthetic technology and group II base oils, getting a 30 point spread in a multigrade (20W-50) meant a lot of polymers, and little was know as to which polymers could resist shear. So if your engine design was for a 50 at operating temperature, you had to spec 20W-50 and hope for the best. Some brands used the expensive polymers, others not. Group II oils didn't become common place until the 90's or later. Once polymer technology improved and group II oils became more standard, you could be more assured of less shear, but sticking with brands that concentrate on quality instead of price. (group II uses less polymers) With the design of good, affordable, synthetics, you can have low temp protection and high temp protection.

I've measured a 4 second difference in oil to bearings between 15W-40 and 20W-50 at 25C. Not something worth playing with.

How was this measured? 4 seconds is seemingly forever,.. wondering what it is at 30 degrees?

Best!

Doyle

[timchar]

My car has a cat, I'm trying to find out what is the best oil for the motor that wont damage the cat? I have read some of this thread but, 4 years worth will take me forever to possibly find my answer. Thanks if anyone can chime in... . Tim

[HarryD]

Originally Posted by timchar

My car has a cat, I'm trying to find out what is the best oil for the motor that wont damage the cat? I have read some of this thread but, 4 years worth will take me forever to possibly find my answer. Thanks if anyone can chime in... . Tim

Tim:

What year is your car?

Generally speaking, the downside of using high ZDDP oil is a POSSIBLE early demise of your Cat. But here some food for thought:

Cats have been in cars since the '70's;
There is no reason not to expect a Cat to last 75-100k+ miles regardless of the oil selected;
Until the mid 90's, most all motor oils contained high levels of ZDDP;
The cost to replace a dead cat is around $2k;
The cost to rebuild an air cooled engine is $10-20k;
High ZDDP will kill your cat prematurely;
Low ZDDP will kill your flat tappet engine prematurely.

Based on these facts, this is how I see it.

ZDDP has not been an issue for cat life until the mid 90's. The cost to rebuild an engine is an order of magnitude higher than replacing a cat.

If I had to choose, I would gladly kill the cat to preserve my engine.

What about you?

[timchar]

Harry, its an 86, I just purchased two months ago. It has 180 k motor rebuilt 25 k ago. I agree with you, better to cook the cat instead of the motor. It was about 10 k to rebuild motor. Thank you for breaking this 5 year thread down to a few paragraph answer that makes perfect sense. I can order my oil now. Tim

[HarryD]

Tim:

Glad to help.

[RWebb]

one thing to add to Harry's comments is that EPA is concerned about long term functionality of the catalytic converter- 50,000 or 100,000 miles

I would use an oil with ZDDP and figure that the car would continue to meet its emissions specs. for many decades at the miles/year that most drive.

[richardlw]

Originally Posted by dshepp806

How was this measured? 4 seconds is seemingly forever,.. wondering what it is at 30 degrees?

Best!

Doyle

It was seemingly forever. First just an observed shocking difference that it took 6 seconds for the light to go off (when I knew it always went off in 2 seconds). So then I looked at my watch, about 4 starts a day for 4 days. That's when I changed back to 15W-40 and total time went back to 2 seconds. Could it have been 6.5 or 5.5, sure. I was not intended to be a study. Just turned out to be.

[Jimmysidecarr]

Originally Posted by HarryD

Jimmy,

Thanks for the update. One question, will the labelling on the front of the bottle help us make the right choice or will we need to delve into the fine print.

I think being familiar with the API-SJ, SL, and the newer SM, and SN oils, and what they have and might not have in them and what value that has regarding protection, is worth learning about.

With that said, for the newer water cooled guys with warranty left our SAE 5W-40 (part #01540, quart bottle) is still an extremely robust oil that is the only API/SAE oil of ours that still has Synerlec even though it is within the API-SM 800ppm cap. Even air cooled guys could use this in the winter months if you have stock cams and you are not putting in a lot of hard core track time.

Oil companies have choices and can buy cheap ZDDP compounds or very expensive ones. The cheaper ZDDP has higher volatility and when combined with an engine that is burning a good bit of oil can in fact poison cats. That scenario is exactly why the OEs went crying to the API about reducing phosphorus, after the feds at the EPA told them they had to extend the warranty on cats.

We don't use cheap components, and we have been buying and using only the very best ZDDP additives available all along. Our XPR is our best oil and also has the most of this compound, yet unless you are smoking like a mosquito sprayer you are not going to poison your cats with this or any of our performance non-API oils.

The main motivation was that if your anti wear protection gets vaporized your oil does not protect as well after a while. If it stays in the oil protecting metal parts and not getting vaporized the side benefit is that your cats stay happy too.

[Reiver]

Originally Posted by richardlw

It was seemingly forever. First just an observed shocking difference that it took 6 seconds for the light to go off (when I knew it always went off in 2 seconds). So then I looked at my watch, about 4 starts a day for 4 days. That's when I changed back to 15W-40 and total time went back to 2 seconds. Could it have been 6.5 or 5.5, sure. I was not intended to be a study. Just turned out to be.

Question. How much pressure does the light switch require to go on/off? Since you need about 9lbs of pressure per 1 k rpm the light on doesn't mean there is no oil at the bearings. You have the residual and then pressure builds to the switch's bult in release and the light goes off.
It def indicates a thicker oil or colder temp but am not sure it is because there is no pressure or oil circulating or that it does any harm at all.....
When I start my 911 with 20/50 (not too cold in Az) when it is colder (high 30's low 40's) in the am the pressure guage registers immediately.

[dshepp806]

My pressure light extinguishes very quickly upon cold starts, even in the winter months (at 20 degrees) with BP 20W50. It's acted this way for 6 years now!!

Doyle

[db_cooper]

While I do not completely agree with the conclusions in this test..it makes interesting reading. ZDDP not really needed?

http://www.blackstone-labs.com/Newsletters/Gas-Diesel/November-1-2010.php

The oil thread that would not die.

[911pcars]

Residual oil between the bearing surfaces should provide adequate metal-to-metal protection during cold starts (given recommended cold run operation). However, be aware that the oil pressure gauge reads system pressure at some remote location, not necessarily at one's location of interest. Some areas only receive adequate pressure and volume X seconds after startup, not right away.

Sherwood

[HarryD]

Originally Posted by db_cooper

While I do not completely agree with the conclusions in this test..it makes interesting reading. ZDDP not really needed?

http://www.blackstone-labs.com/Newsletters/Gas-Diesel/November-1-2010.php

The oil thread that would not die.

Mr Cooper,

I suggest you look at post 1597 of this thread and the following thread:
Blackstone and ZDDP

[Joe Bob]

VR1 should be on sale at O'Reilly's soon. Last year it was in March.....