Royal Purple 10W-30, 2001 Toyota Corolla (3ZZ-FE), 6109 miles

[es]

Hi all,
This is my second UOA. My first UOA on Castrol SLX (A1) 0W-30 can be found here.
This is my first time trying RP. It costs around half the price of Castrol SLX over here.

80% of distance covered is on freeway. The weather here in Singapore is warm and it rains a lot.
The 3ZZ-FE engine in my Corolla has an aluminium block and head with cast iron liners.
I was worried about the high silicon / aluminium in the previous UOA. I changed the KNN air filter back to an OEM paper one and the silicon and aluminium did drop a little. So I guess the rest may be from the seals and gaskets.

Comments please. Do I need to worry about the viscosity? Should I stick with RP?
What do the oxidation and nitration numbers mean?

code:

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Car : 2001 1.6l Toyota Corolla (3ZZ-FE engine)



Oil : Royal Purple 10W-30 Castrol Formula SLX A1 0W-30

Miles on Oil : 6,108 6,400

Miles on Engine : 43,604 37,623

Oil Added : 0 0





Metals (ppm)

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Aluminium (Al) 6 11

Copper (Cu) 1 1

Chromium (Cr) < 1 < 1

Iron (Fe) 7 8

Lead (Pb) 1 < 1

Tin (Sn) 1 1

Nickel (Ni) 1 < 1



Contaminants / Additives (ppm)

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Silicon (Si) 40 56

Boron (B) 8 15

Sodium (Na) 5 7

Potassium (K) 4 7

Phosphorus (P) 921 924

Molybdenum (Mo) 157 334

Magnesium (Mg) 8 13

Calcium (Ca) 2227 2514

Zinc (Zn) 1121 1134



Physical Tests

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Total Base Number 2.6 3.7

Water (% by FTIR) < 0.1 0.1

Soot % 0.2

Oxidation (Abs) 34

Nitration (Abs) 12 16.6

Viscosity (cSt,100°C) 9.6 10.4

Viscosity (cSt,40°C) 59.5 57.2

Glycol (Abs) < 0.1 < 0.1

Petrol (% by Distillation) 0.5 0.8

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[Spector]

Both are excellent reports, looks like the RP did hold up quite as well as far as TBN but not worth haggling about. Assuming the price differential is what you say this oil is doing well. The high silicon is not causing wear so either an additive or gasket/seal material.

 

[Pablo]

Very interesting. What lab did you use? (Pardon me if I missed it in the post)

Actually both oils served you pretty well. I don't think you can say one is better than the other.


That Castrol has moly. Yes and the RP did thin. TBN seems low...Blackstone?

Oxidation in simple terms is the oil breaking down from abuse and heat. Numbers depend on a scale (sometimes 0-100 or 0-200 or other) and comparing to virgin is important.

 

[es]

The lab is WearCheck.
What's an acceptable TBN? Do I have to worry?

 

[Schmoe]

I'd be more worried about the silicon, yikes!

 

[Bror Jace]

There's essentially no difference between the two oil's performances. I'd go with what's cheaper.

Judging by that TBN, you're right at the limit of what that oil will take. Don't go much, if any further.

Silicon does look alarming. On the good side it is trending down and wear is pretty decent throughout.

I forget who on this site once pointed out that newer toyotas show high silicon for the first year or two from gaskets, etc ... but I'd double-check your air filtration just to be sure.

--- Bror Jace

 

[Bio-T]

ES,
With Royal Purple costing 1/2 as much as the Castrol, the decision is not hard to make on this one if I were in your situation. Your wear numbers are low and the Royal Purple held up very well. I have no personal problem using any of the Royal Purple API synthetic oils. I don't need or use any of their Race oils, so I can't comment on them.
Thanks for the UOA on this oil in this engine.

 

[Patman]

Definitely stick with what's cheaper here since the results are so similar. It's funny how it would actually be cheaper for you to use an American made oil as opposed to one that is made over there closer to your end of the world.

Here in Canada, Royal Purple is a few bucks more than Castrol Formula SLX 0w30 (although I realize the stuff you were using is different, since the stuff we have does not use any moly in it's formulation)

 

[Ken4]

quote:

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Originally posted by es:
What do the oxidation and nitration numbers mean?

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I asked that question a long time ago. Here are some answers. It also depends on the scale they use. Is it 34% and 12%? Or if the scale is 0-200, then it would be 17% and 6%. Ask wearcheck.

And watch out for the high silicon. Your silicon did drop when you switched from K&N back to OEM. Some could still be residuals, but 40 is still way too high. Unless you've done some work on your engine involving new sealants/gaskets, your toyota is well past break-in and should not leech silicon anymore. You may also have to clean out the insides of your air intake hose & TB from dirt and oil accumulation. Or you may have an air intake leak somewhere.

quote:

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There are several tests which can detect false air entry into the induction system. A good visual inspection of the intake air connector pipe and connection pipes as well as inspection of all vacuum hoses, engine oil filler cap and dipstick seals are a must.

If this fails to identify a suspected leak, spraying carburetor cleaner around suspected leak areas while observing an infrared exhaust analyzer for carbon monoxide increase is another method to assist in leak detection.

Another method to locate suspected false air entry points is to pressurize the intake system with regulated shop air supply (CAUTION: do not exceed 25psi). Spray a soapy water solution around all suspected leak areas. Simply listen and observe for bubbles to locate leak sources. This method requires sealing the air cleaner fresh air inlet and blocking the throttle valve open to pressurize the intake air connector pipe. The air pressure can be applied through any large manifold vacuum fitting.

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[es]

Thanks for all the informative replies.

I'm a little concerned about the silicon levels and will recheck my air intake path. Some others have mentioned that high silicon without abnormal wear metal levels (Fe, Cr, Pb) are ok.

I guess it's better to be safe than sorry. No point doing a UOA if you're not going to heed the warnings.