The Nulon 10W-40 MSDS tells this:
Page 1, section 3 COMPOSITION / INFORMATION ON INGREDIENTS
paraffinic distillate, heavy, hydrotreated (severe) CAS 64742-54-7. >60%.

As far as I can tell its dino oil, a Group III+ base stock.
Not a word about PAO or esters or any other true Group IV or V syn base stocks.
CAS 64742-54-7 is hydrocracked dino, not bad stuff but no true syn.

The Nulon 10W-40 is fast flowing though


If you want to stay with Nulon, I would suggest their 5W-30 Euro Engine oil for the S2000.
That MSDS lists 1- decene homopolymer, hydrogenated 68037-01-4 in a 10-40% content.
The CAS nr 68037-01-4 shows it is some kind of PAO, as in true syn.
A mixture at best though as CAS 72623-87-1 is also a Group III+ base stock as far as I can tell.

But I think I know what happens with your oil turning black:
Is the store owner someone you know personally?
When you come in to buy your fresh oil he by now knows you're changing it out way too soon.
So he finds a way to drain your good oil to replace it with his black old oil.
That way you continue to use your oil change interval (your oil suddenly turns black = time to change) and he does not have to pay for oil.
Also good for the enviroment as good usable oil is not going to waste.

 

Of course you're not. That's why you correlate the color of the oil to the rough running. "Indubitably, my dear Watson, indubitably!"




Checking out. Thread getting way too entertaining and I didn't buy a membership.

 

I'm glad somebody finally mentioned it. If you want to know what your engine is doing, get the oil analyzed. Get the TBN if you want to see how well its holding up. Color is nothing.

 

[/quote]
Of course you're not. That's why you correlate the color of the oil to the rough running. "Indubitably, my dear Watson, indubitably!"


Well as soon as I change it it's running smooth again so it makes sense to me. I also checked the plugs and they are fine.

When the oil was black it just felt a bit rough and as though it wasn't making as much power. Not majorly rough, just not as smooth as it should be.

As soon as I do an oil change it feels as good as new.

I think that is enough reason to correlate black oil with it not as running as well as it should.

 

The makers of "Slick 50", Duralube, STP and Super Duper Tinker Bell Octane Boost love people like you, not to mention hundreds of psychologists in your area. Have you tried Royal Purple? I hear the color purple takes off 50,000 miles from the age of the car.

 

What is your problem?

Are you on these forums just to troll?

If you don't have anything useful to say then don't post.

Can't even ask a f@#kin question on here without 1 or 2 arrogant know-it-alls trying to put the less experienced down.

 

I change my oil every 9-10k miles and I daily mine with over 155k miles on it. Perfect compression. It's all in your head. It's the placebo effect. Seriously, the color has ZERO to do with it.

 

Try reading actual advice. Colour means nothing.

Pro tip: Listen to everything Billman says.

 

The correct answer was given several posts prior to this by a non arrogant expert. Apparently, the question still wasn't answered. When the question has been answered and the 'less experienced' keep on asking because they haven't enough experience to realise there is no longer a question then the tongue in cheek comments start - that is internet law 101. It's also the same reason that people who can't do basic maths don't end up designing nuclear reactors

For what it's worth - i change my oil twice a year irrespective of mileage. I use a winter grade oil from November through till March and then a summer grade oil from March through to November - both turn black with use ( frequent short commuting does this faster) and it doesn't worry me at all, the cars performance doesn't suffer and it's not gulping oceans of the stuff between changes.

I'm still not good enough at maths to design a reactor pressure vessel but I CAN spot the right answer to a question.

 

The more I read the specs of some of the Nulon oils the less impressed I get.
It's all dino or dino/syn blend, AT BEST.
TBN's I've seen are not very high, even the 5W-30 longlife oil only starts at 7.2
Top quality true syn oil can have a TBN as high as 12-13.

The oil the OP is using, 10W-40, is also pretty thick at 14.4 cSt @ 100C compared to the Honda OEM recommended 30 weight oil.
They are around 10 cSt @ 100C and that's the viscosity the F20 was designed around (IMO)
You're loosing power right there, that's a fact, like pumping loss and oil drag.
Also, you're loosing oil flow through the engine at higher rpm's, another fact.
That said: its pure dino oil so it will shear down (= get thinner) within the oil change interval.

Nulon does not give the HTHS, a value to show the oil's capability to deal with high temperature AND high load conditions.

My free, unbiased, honest advise: stay away from Nulon.
It may be cheap, I donno, but you're not getting very good oil.
If it's expensive, definitely run away from it.

What else is there available where you (OP) live?



@ unclefester
Oh.. btw... there is NO summer and winter oil anymore, not even in the UK.
Unless you are using oil your grandfather stashed during the 40's, next to the Jaguar E-type restoration project of your father.