The NS is not part of the viscosity index. The NS belongs to redline. The viscosity index should read as Redline 75W90 NS. Notice the space between the 90 and NS.

For redline, the NS series of gear oils do not contain any friction modifiers. Normal synthetic gear oils are too slippery for LSDs. The NS series are made specifically for gearboxs with LSDs.

The colour of the engine oil after usage is determined by the condition of the piston rings. Worn out piston rings will allow blow-by from the combustion chamber into the engine. This will dirty any engine oil, including the ones you are selling. Put your engine oil into an old car and you will see that effect.

There are 2 types of dark engine oil that comes out of the engine. A good condition engine will still produce dark coloured oil at the end of the service interval but that is only due to dirt suspended in the engine oil. The oil still feels like oil. However, if a bad engine oil is used it will not only come out black but it will come out like sludge. The oil feels like watery gum.

As long as there's no sludging and the oil consistency has not changed, the colour of the oil will not reduce the performance of the oil unless you have a really bad case of blow-by which will turn the engine oil black within the first 1000km. That would be an engine problem and not oil problem.

This post has been edited by sleepwalker: Sep 19 2011, 09:16 AM

That would work only if your engine does not have a MAF sensor.

That's because they are using MAP. MAP is not MAF. MAP is the alternate to having MAF. Fuel injected engines are built with either MAP or MAF but seldom with both. Like I said in my previous post, your it works only on cars without MAF.

This post has been edited by sleepwalker: Apr 11 2012, 09:28 PM

Pressurised air after turbo. Going to mess up the MAF. That is why the MAF is placed before the turbine so that it can measure unpressurised air going into the turbine.

That's where most people do not understand the workings of the engine and then wonder why they can't stretch the oil change intervals. It has nothing to do with the degrading of the engine oil but rather the contamination of the engine oil that shortens the oil change intervals. BMW tried their EURO standard 25k km oil change intervals here and ended with slugging issues and dead engines.

The oil itself will last a very long time if there are no contaminants. For example, gear oil works harder than normal engine oil but last much longer as there are no contaminants being introduced to the system. With every combustion of the engine, blow-bys leak past the piston rings and into the engine. Every stroke of the piston, you are introducing petrol, moisture, acid and carbon into the tiny 4-5L capacity of engine oil. All these contaminants has nowhere to go and resides in the engine oil. The oil filter is only good to remove large particles of contaminants but not things like water and acid.

I change my full syn every 5000km not because the oil is dead but the oil is dirty. Here are some numbers to crunch.. if you drive 5000km at 100km/h, at 3000rpm, it will take you 50 hours to complete. 50 x 60 x 3000 x 2 (each rpm is 2 strokes, up and down) = 18,000,000 strokes. How much junk do you think would have gone past the piston rings after 18 million strokes up and down? That is only 5000km at a constant speed.

Added: Oh yeah.. I forgot.. that is only for 1 cylinder.. if you have 4 cylinders, multiple that by 4.

This post has been edited by sleepwalker: Apr 25 2012, 02:46 PM

Engine oils should not degrade an engine performance unless it is becoming sludge. That is usually caused by the introduction of contaminants and not the breaking down of the engine oil.

In the case of same engine, different rate of engine oil deterioration would be cause by the amount of the additives in those engine oils. The additives in engine oil is providing the primary protection and not the base oil itself. Some engine oils have less additives and will start slugging much earlier than others due to the contaminants.

Broken down engine oil turns watery and not sluggy. I have used the same semi-syn in a 1.3 and then later in a 1.8 turbo. In the 1.3 it was fine.. in the turbo.. after only 2000km, the oil consistency turned to almost water but it was not black or contaminated. However this only applies to a few engines using wrong type of engine oil. The majority drivers out there will not see this happening.

This post has been edited by sleepwalker: Apr 25 2012, 05:32 PM

The base oil plays a part but it is not a quantifiable part. You can't rate the engine oil by the base oil and hence is not used as a rating. This is how fully syn oils are superior against mineral when it comes to protection against the oil breaking down. Similarly some manufacturers use the process of hydro-cracking to improve the base mineral oil, to a point where some even try to be 'Pretend' Synthetics.. no thanks to Castrol for labeling Group III oils as Synthetic..

So the base does play a part.. like an actor in a movie who is not credited at the end.

Like I said, it's non-quantifiable part but it still plays apart. Tiny but still in play. Similar to my case where I destroyed the engine oil in 2000km and turned it to water. That's the base oil giving out. And I repeat myself that most people will not experience what I have gone through. Car and track enthusiast would understand what I'm talking about as most people don't turn oil to water. MOst turn to slug as they have not over worked the oil beyond its design. Some of us have driven our cars hard enough to do that.

With full synthetic, at 5000km it comes out all black due to the contaminants but the integrity of the oil is still there due to the superior full syn base oil. It still feels like oil and looks like oil with suspended dirt. It has not turn sluggy so it hasn't been over-contaminated.

We were testing oils. Wrecked the Castrol Magnatec in 2000km. The engine didn't fail, the oil did. The engine went on for another 60k km before I sold it and it lasted another 40k km with the new owner before the turbine gave out. We just drive a lot harder than most people. We were looking into the effects of using semi-syn and how we can wreck it in turbo engines. At that time when we did the testing, most did not believe that semi-syn only had 5-10 percent actual synthetic to be labled as semi-syn. We were out to prove a point. That was about 12 long years ago.. how time flies..

This post has been edited by sleepwalker: Apr 27 2012, 08:26 PM

Rather interesting reply from Torco and a lot will think, wow.. definitely good stuff. Then again, if you do a little research into why API has been reducing the amount of zinc in the engine oil, you will understand why Torco can't get the API donut.

Check this link to know why API standards have been reducing the zinc content.

http://www.streetrodderweb.com/tech/0803sr...il/viewall.html

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Added on July 31, 2012, 3:46 pmViscosity does not translate into protection. Film strength provides the protection from shearing but there is no film strength indicator. Viscosity just means the fluids resistances to flow which is another meaning for being thick or thin. A lower viscosity number does not always mean lower protection.

This post has been edited by sleepwalker: Jul 31 2012, 03:46 PM