[R3x]

Googling for Engine Oils say SJ (and above) is good, for modern bikes. But some "unproven" facts say (i read somewhere) that SJ rated oils, when used in motorcycles with wet clutch, can cause the clutch to slip.

My question is:
1. What is clutch slipage & how does it damage?
2. Is the above fact true (going by experience)?
3. What is wet clutch/dry clutch & how do i know what kind is my mobike?

HH recommends me to use SJ 10W30 on my CBZ Xtreme. Why should i not use 20W40 or anything else for that matter? (Well... i really can't see why, because i am not driving in extreme weather conditions anyway)

edit:
correct me if wrong.. when we say 10W30, the grades for oil mean -
10,20,30,40 ->thicker, thick, thin, thinner ?
or is it otherwise?

[Yogesh Sarkar]

First of all, forget about every thing and try and stick to the engine oil grade recommended by your motorcycle manufacturer. Switch to a different grade only if the situation demands i.e. excessive heat or engine roughness.

SJ rated engine oils will not cause the clutch to slip, as long as they are JASO MA compliant (which basically means it is for wet clutch engines).

Majority of the motorcycles in India have wet clutch, barring the Royal Enfields. In wet clutch system, the clutch plates are immersed in engine oil, that’s why friction modifiers which reduce the friction can cause the clutch to slip, since it needs friction to operate.

For the basics of engine oils, check out Car Engine Oil Bible (basic principles are the same).

[apache_rider]

Its the other way...10,20,30,40..--> Thinner, thin, thick ,thicker and yeah these figures mentioned are after the W and not before that..

CBZ-X recommended grade is 10W30 and using in xxW40 oil means that the oil is thicker.

The oil is okay for wet clutch application is decided by whether the oil confirms atleast to JASO MA standards. Currently all newer batch of oils confirm to JASO MA2(companies claim so).

1) Google baba ki jai..!
2)Not exactly true look for JASO MA or MA2
3)All bikes made in India(except for RE's) have wet clutch type engine setup

If you are not riding in extreme conditions, then stick to 10W30 or else if you want to switch to synthetic oil then look for xxW40 synthetic oil..

[R3x]

The problem is that the last couple of times i've not been able to find 10W30, and hence i had to go for 20W40.
I wanted to try petronas sprinta 5000 this time, but i believe switching from mineral based to synthetic involves a little more than just a oil change to start with. So went for motul 3000 4T plus (20W40 again) this time. (Would have had put sprinta, but the engine oil vendor said no flushing is required. wanted to confirm before i really take his word and screw up something)

[Yogesh Sarkar]

No need to worry about flushing. As for the 10w30 oil, it should be available at Hero Honda service centers, since it is being recommended for almost all their vehicles. Also if I remember it correctly, Castrol had introduced a 10w30 synthetic oil in India, you might want to check with them.

[apache_rider]

Go ahead and switch to synthetic. btw Castrol has launched 10w40 synthetic oil