juz sharing ...
the viscosity grade (for example, 5W-30) tells you the oil's
thickness, or viscosity. A thin oil has a lower number and flows
more easily, while thick oils have a higher number and are more
resistant to flow. Water has a very low viscosity - it is thin and
flows easily. Honey has a very high viscosity - it is thick and
gooey.
multi-weight oils (e.g. - 10W-30) are a new invention made possible
by adding polymers to oil. The polymers allow the oil to have
different weights at different temperatures. The first number
indicates the viscocity of the oil at a cold temperature, while the
second number indicates the viscosity at operating
temperature.
