I have Bridgestone Potenza RE040s all round on my 18s and they have protection built in. They are sh@g all use in the wet though! 
I just don't get why peeps like rice . . . I mean Bridgestones - they are $h!te in the wet in F1, cr@p in MotoGP . . .

OK, maybe fit rice tyres on a rice burner, if you are that way inclined - but on quality German engineering . . . Nooooooooooo!
