the first number b4 the "w" stands for the minimum operation
temperature. it applies to seasonal countries where temperatures
can sometimes drop to below 10 degrees and therefore they have
different grades for different seasons. for example: 10w40
lubricant is more suitable at 10 degree celsius and above
temperatures. though i never seen 0w40 b4 but wat that means is its
practically an antifreeze and therefore costs alot. in singapore
that number makes no difference as our temperature rarely drops
below 20.
the 2nd number is more important. it stands for the viscosity of
the lubricant, meaning how thick it is. thicker or thinner is
engine and driver/rider preference and normally prices dun defer
much.
a 10w20 gear oil is thin and runny and very smooth but engine will
overheat very easily, lubricant breaks down faster and generally
louder engine noise.
a 20w60 4T (which only AGIP has in singapore) is very very thick
and may cause extra stress to an engine not suited for its use due
to the greater turbulence. this is mainly for high revving, high
powered engines that overheats easily like the Ferrari and other
luxury sports cars (no not the ahbeng WRX, we talking lambos here)
and i wouldn advise using it on a bike...
hope dis is helpful.
