We've all done it - put the wheels of our car into an icy rut and lost traction. It's called getting stuck. Tires spin, foul language fills the air, and someone always says, "Don't spin your tires!"
The science of getting unstuck!
By: Alan Nursall
Is this good advice? It helps if we understand how tires work. We all can intuitively understand the importance of friction between the tire and the road surface, and that's great if you're on dry pavement with a dry tire. But when friction disappears, it's the tread of the tire that needs to take over!
Tread serves two main purposes. First, it provides channels for water and wet snow to be pushed off to the side, allowing the tire to get down to pavement. And just as importantly, the tread grabs onto the surface and pushes material backwards. That push backwards provides a force forwards. One of the best analogies I can think of is the old riverboat paddlewheel. The paddlewheel pushes water backwards and that propels the boat forward. It's Newton's third law! The tread of your tire is like the paddlewheel, except instead of paddles sticking out, the tread is incised into the rubber. But the effect is the same.
That means if you want to help yourself get unstuck, let your treads help! And that means not spinning your wheels so that the tread has an opportunity to get some grip! You may still need a push or a tow, but spinning doesn't accomplish much of anything, other than put a very fine polish on the surface under the tire!