OK, I read this thread and followed all the posts and went ahead and bought a groover. I did all 4 tires and it took about 45 minutes per tire at 20 degrees. I'm anxious to try them during the next snowfall. I did this on a JD2720. <img src="http://www.tractorbynet.com/forums/files/snow-removal/410044-cutting-groving-siping-r-4-a-2-3-2015-rear-tires"/><img src="http://www.tractorbynet.com/forums/files/snow-removal/410045-cutting-groving-siping-r-4-a-2-3-2015-lf-tire"/><img src="http://www.tractorbynet.com/forums/files/snow-removal/410045-cutting-groving-siping-r-4-a-2-3-2015-lf-tire"/> Many thanks to all the contributors of this thread. I could not fit chains on my tractor since I have the optional mower lift option and hope this takes care of my traction issues without the need for the expensive spacers and tire chains. My tractor does "OK" for the most part but has also disappointed me in certain snow/ice conditions. You guys are a blessing.