Both of them are bad for the rubber compound.

 

I got this from Michelin site......
They will not warranty for damage from certain chemical based tire dressing.

 

Hmm nice to know but since most do not list this info on the can how do we find out?

Richard

 

Most of them DO list the info on the can. If it contains silicones, it contains petroleum distillates. The only one that I know of which doesn't have these compounds is 303 Aerospace Protectant. I generally scrub the tires with car wash detergent and a towel, then apply a small amount of 303.