in my many years of playing with tires, i have done things most here would find disturbing. like mounting a 5.60 vw tire on an 8" rim, and mounting a 13.50 dirt tire on a 4 1/2" rim, just to see if it could be done. would it be recommended ? uh, no ! but.... also, i have run the spectrum of narrow to superwide matching wheels and tires most manufacturers of both do not recommend with sometimes excellent results. usually, one can get away with one to two inches wider or narrower than recommended tire or wheel width without causing major issues. you may, or may not get the maximum life out of the tires, but you won't know it if your tires dry rot before the tread wears out. your opinions and results may [more than likely] vary.