Originally Posted by vq40
In a nutshell I'm not going to write a big article but, DPF filters out larger soot particles, and then when it goes into regeneration, it burns the larger soot into smaller particles then out the tailpipe. Oil volatility plays a part in that soot . The DPF will not catch that. Volatility is highest at the beginning of oil change, and will stabilize after the first 3000 miles. So that's the reason for the extended drains as well of 10,000 miles. VW has tested all this and, with the way VW regeneration works the oil has to withstand the fact VW TDI engines with the DPF deliberately squirt an extra shot of fuel into the cylinder on the exhaust stroke to heat up the catalytic converter in order to regenerate. A portion of this fuel will end up on the cylinder walls, be scraped up by the piston rings, and end up in the crankcase, where it will dilute the oil. The oil must be designed to tolerate a certain amount of fuel dilution.
Did you read my questions or you just spewing your assumption?
You do know that Mobil1 carries VW 504.00/507.00 approval? I actually worked on testing of oil that was developed for that specification and there is no one oil that has special treatment by VW and then rest. LL03 carries only VW504.00/507.00 and NOACK can by anything as long as it is below 13%. Knowing Castrol, it is probably around 10-11%. It does not meet MB229.51 so NOACK does not have to be below 10%.
Do not get me wrong, it is good oil, BUT not on par with Mobil1 ESP Formula 5W30 that had apparently NOACK of 5.6%. But, even if that is not true, we know that VISOM base had some stellar NOACK results in other oils like 0W40 which was 8.7%.
The DPF WILL CATCH oil composition. That is why DPF has lifespan. It is clogged by SAPS which ends up in DPF through oil volatility.
I know how fuel dilution works.
So, my question AGAIN is: why Castrol 5W30 LL03 is better than Mobil1 ESP Formula 5W30 if BOTH meet VW 504.00/507.00?