[dean from bozeman]

Here's a question for you old timers or someone who learned from an old timer. Is there a "homegrown" method to determine an oil's viscosity?

Basically, how can you tell whether a car has winter or summer oil?

I remember the Prell shampoo commercial when I was a kid. They would put a pearl into a bottle of Prell and it would slowly sink to the bottom. Now is there a way to test motor oil.