I know your supposed to run 4 tyres thatare exactly the same, but are there any serious problems, dangers etc if you had say 3 Pirelli tyres and one continental ! Is this just tyre people wanting you to have 4 of their tyres on. Blown a tyre on my M3 and on the Modena (nail). Modena is fine, tyre been repaired. On my M3 however i was half way up the M1 and the garage i was taken to had only 1 tyre that would fit the 19 inch alloys, different to the others. Should i buy a new tyre to match the others, or is it perfectly fine to run the 4 that are on now ?