Originally Posted By: Ducked
Long time ago I looked for data on tyre performance related to tread.
There was very little, and mostly negative. IOW there was little or no consistent effect of tread depth on stopping distance. Stopping distance isn't of course, the whole story, but its relatively easy to measure.
In the dry (most of the time here) bald tyres actually worked better, which isn't all that surprising.
So a penny would be fine for me, if I had one.
Well...a long time ago was...a long time ago.
Please read through the Tire Rack links that I provided. Testing shows, conclusively, that decreased tread depth has a significant impact on wet and snow traction.
Snow may not be a problem where you live, but rain certainly is, and a tread depth below 4/32" will reduce your wet traction.