Engine Oil for the S2000

[AusS2000]

Then please explain what the two numbers either side of the w mean. Is it not true that the higher the number the more resistance to flow (internal friction or viscosity) hence using 20w50 in older low revving engines?

My understanding is that simple fluids decrease viscosity (get thinner) with temperature fairly linearly. Hence traditional oils have a single viscosity number. Friction modifiers were introduced as a clever way of reversing this trend for a range of the temperature. Ah the wonders of modern science.

Happy to be re-educated.

[gumus89]

Then please explain what the two numbers either side of the w mean. Is it not true that the higher the number the more resistance to flow (internal friction or viscosity) hence using 20w50 in older low revving engines?

My understanding is that simple fluids decrease viscosity (get thinner) with temperature fairly linearly. Hence traditional oils have a single viscosity number. Friction modifiers were introduced as a clever way of reversing this trend for a range of the temperature. Ah the wonders of modern science.

Happy to be re-educated.

The W signifies that the preceeding number is the cold specification of the oil. The second number is hot grade.
They are not directly referring to viscosity although you can compare first and second numbers between oils. as in 5W-30 and 10W-30 have the same viscosity at high temp but the 10W is thicker at start up.
aaronng explains better.