When we had the cold air invade us and the snow fell last weekend, my smart car had no problems up to about 3" to 4" of snow. Then after a couple of days, the roads became packed with ice and compressed snow. The kind that turns the roads into a washboard affect. When that happened, the ContiProContacts started to fishtail my smart car. If you anticipated it, you had no problem keeping it under control... but you had to constantly be on-guard. I've had other cars and have never had this problem before at speeds around 15 to 20mph. So I thought I'd put chains on. It didn't change a thing. Other 2-wheel & 4-wheel drive cars would pass me.
Again, soft snow was not an issue. It was after a couple of days of constant driving where the road looks polished and choppy. My smart's rear end wanted to "weathervane" towards the right side of the road.
Today I had my BLIZZAK LM-18's installed and went down the same road. Those tires stopped the slippage and solved the problem. When conditions permitted, I even took it up to 40mph without any slipping what-so-ever. I felt completely under control.
The BLIZZAK LM-18's were definitely worth my investment.
-Tom L.