Engine oil update.
The Shell Advance Ultra has been going well with the bike.
Oil consumption is still there, but not as much as the Motul 7100. Done around 1000 km from the previous oil change. I has to use the remaining 300ml to top up. The oil level after top up is slightly above the max mark. So, I guess the actual drop was something like 250ml.
There are no leaks or white smoke from the exhaust.
Previously with 7100, I had to top up 200ml in 600km.
Something else that I noticed with th Shell Advance Ultra is that the oil has darkened considerably. I mean, it's pitch dark when seen through the glass window.
I have previously only used 7100 and 300v. None of these oils used to blacken as much as the Shell did even after 4000 km.
Is it cleaning the engine carbon deposits which the Motul didn't clean? Or is it just degrading quicker?
There is no reason for any sludge deposit in this engine because I have never run without an oil change over 3000 km.
Since the oil consumption issue is not resolved, I'm thinking about using a thicker oil. This is a classic solution which works. XW60 oils have been used by a few abroad and reported positive results. But this grade is not available in India. The best bet I have is 20W50, which is the recommended oil grade for Duke 200.
But, this makes me think. Why did KTM specifically recommended 15W50 for the 250 and 390 while they were already using 20W50 for the 200. Wouldn't it have been easier for them to have just one oil grade for all the bikes?
From my past experiences with using slight deviations from the recommended oil grade, I have not noticed any issues.
This also makes me remind of what happened with Maruti Suzuki. They used to recommend 5W30 for K12 engines. Later they changed it to 0W20 and then to 0W16. But the ASC fills 5W30 most of the time. And with these ASC, it's not like we can confirm they filled what they billed us for or not.
Oil consumption is normal is newer engines today.
BMW for example, has said that some of their engines can consume up to 1 quart of oil for every 750-1000 miles driven and that it’s normal.
That's 1L per 1200km is normal!
The Duke 390 engine is a highly stressed unit and with a compression ratio of 12.8:1, it runs so hot. I guess the oil would get sucked past the cylinder walls and rings when ridden hard.