i've always treated my engine with semi-synthetic oil before. petronas, mobil, etc, as long as it's a semi. mostly petronas. viscosity? not sure. never took it serious anyway. as long as the engine runs smooth, light, and reliable, then it's fair enough for me. no need to go too technical. it'll mess your head. change every 5000 kms.
i've also use a fully synthetic. my personal opinions, better change it every 5000kms also. dont wait until 10k(actually, even at 8k), coz by then the engine feels heavy already(even if you changed the oil filter at 5k). dont know where the myth fully syn = 10k came from.
minerals, use only twice, dont like it. what's the point if your engine feels heavy and growling.
FC, didn't really took it serious..hehe.by the way that i drive, FC has to be put aside. of coz, lighter engine revs should save your FC a lil bit.
This post has been edited by fatani: Jun 24 2009, 02:55 PM