30W is definitely thinner than 40W and the Honda LEV 30W is a great mineral oil. These 10W-30 are what we call Kancil oil la..
Castrol also got.. M-Tec but 3L only..
Oil thin,of course got pick up lor.. best drain every 5k km, if not 3k km..
My regular spare part shop sells a lot of LEV. Mobil 1 has 0W-20 while Royal Purple has 0W-10, which I think can easily vaporise in our climate..
Oils are getting thinner for fuel efficiency, and drain interval to be extended for environmental friendliness. Its seems for the bigger picture, protecting the environment is more crucial.. low sludge oil are a main challenge and now they are working on GF-5 standard..
more.. which specifically focus in low sludge so drain interval can be extended and of course, to improve fuel efficiency, piston cleanliness and cleaner emission.
Now, who say sludge is not cause by oil? read on..
Oil sludge
From Wikipedia, the free encyclopedia
Oil sludge or black sludge is a solid or gel in motor oil caused by the oil gelling or solidifying, usually at temperatures lower than 100 degrees Celsius. Sludge can be a major contributor to Internal combustion engine problems, and can require the engine to be replaced, if the damage is severe. Sludge is usually caused by the presence of water in the oil, and can accumulate with use. Ways to minimize sludge production and accumulation includes performing frequent oil changes, using synthetic oil and following the manufacturer's engine maintenance routine.
Source: http://en.wikipedia.org/wiki/Oil_sludge
So, sludge is cause by water.. !!
is anxious reading this?!