If you did a cold test on straight 30 weight oil, it would come up as 30 weight. Like the chart I posted, it would have a dynamic viscosity of 1.53+/- N s/m^2 versus a dynamic viscosity of 0.01 N s/m^2 at 100C.
The only thing that would change that would be adding viscosity index improver to the oil, which would then make it NOT straight 30 weight.
In other words, straight 30 weight oil is ------ wait for it -------- straight 30 weight oil.
