I used them in the snow today, and they worked well..It was not a really good workout but I was nose down on a very steep snow/icy hill the wife's 2006 Impala was stuck on this hill, just would not go up it. She hit the hill too slow and with traction control on, would not go up it. I got in the car and carefully backed it down all the way, and part of the way up the other hill as far as I could go. (stuck between 2 hills) gave it the gas the traction control cut in, and I ran out of momentum. I was done with that idea, as the back down was a very harrowing experience trying to not lose the car in the bottom of the ravine (20 ft down). It wanted to slide off and not roll the wheels just slide down the hill. Very difficult to keep it straight not go to fast, keep the wheels rolling etc. I lost my 2000 Silverado a few years ago doing just that , got going too fast and the rear end swung around went halfway down the ravine on the "good side". I was lucky to get out unhurt, truck was unhurt, and paid $300 for the wrecker to pull it out with a double snatch block hookup from about 300 foot away. Anyway I backdrug the snow and ice from in front of the car as close as I could get to it, and shoveled the rest out from in front of the wheels, and brought some frozen road base gravel from my pile to spread in the road in front of the car and under the tires. The tractor never spun a bit on this steep hill backing up and dragging the snow uphill. I then drove the car up hill on the spread gravel under its own power. Would the tractor been this good without the grooving? Hard to say, I did not have an identical tractor/tire setup to test. I had some trouble spinning last year with the ungrooved R4 tires in a neighors driveway trying to drag out the snow, that was not as steep as this road. I had to abandon the idea of dragging out the snow, and we did it with shovels. I noticed the snow filling in the grooves just like everyone says. So this is not a super good test, but the tires did well today. Far better than a 2006 Impala with traction control.
James K0UA