My opinion seems to differ.....I love siping. I have had 3 sets of tires siped on 3 different cars with nothing but "great" results. Siping DOES decrease tire life and INCREASE the chance of pieces of the tire coming off but the traction gained is amazing. I have never had a problem with the tire coming apart or stability problems and I drive my SVT as hard as anyone could. Think about how many times your tire gets a little cut from running something over. I wouldn't sipe a good or new tire but if you have an old all season or worn snow that needs a little life. Sipe em! What I do is buy a good new set of tires every year. Run them to death all summer then sipe the best 2 and mount them on the front. Next year throw them away and start over....Kumo's are $70 or so a tire...Sipe em and you have a free snow tire. Siping is NOT a replacement for a snow tire by any means but can easily double the amount of traction your getting from an all season or other tire. And as far as a warranty goes...If you have them siped from the same dealer the tires are from they ARE still under warranty(at least with Discount).
