That must have been my problem. Most of what I was driving on was icy-wet or snow-covered roads. Any deep snow I drove on was usually iced over a bit from teperature changes. I can see where if it was nice deep soft snow, the tires would grip it just like mud or some such stuff.

 

i spin the tires with my I-4 in my truck......

 

so, can you sipe your tires with just a razor blade?

 

That would be rough. I think the tool looks similar to a utility knife but I think it has some heat to help it slide through the rubber.