reccomended tread depth when only replacing one tire.

so, just got my alltrac running again, and wouldnt you know it, one of my 4 year old maxxis Mav-1s blew out. Too bad, because they have most of their tread left.

I wanted to replace just one tire for economical reasons ( saving every penny for my RA ), but im having trouble finding the tire locally, and dont know how close the rest of the tires need to be to new tread to avoid differential damage.

So thats my first question, how much tread do i need on my remaining three to be determined safe for use with a new fourth tire, should i be able to find one.

If not, then my second question is what is the best tire i can get for a good value if i have to replace all four. She sees mostly seattle winters, so a decent all season is acceptable, they dont have to be dedicated summer tires.

final question, currently i have 215 40 17 tires, how much higher could i go on the sidewall without rubbing or looking funny? 50? 60?!

Thanks guys, I'll also be re-reading the big tire sticky a few times to bone up on all of this.

I can help with the first question, if the new tire has more than 2/32 of tread than the old tires it is recomended to change all 4

If the new one is too big, just put in on a FWD Celica with an open diff and do burnouts til they're even.

Thanks for the solid info, guys.

Got a tread depth finder and measured between 9 and 10/32nds all the way around. New tire depth for the replacement is rated at 10, so based on the advice i should be good to replace just one without fear of diff damage.

thanks guys, this was really helpful, while not an ideal solution it helps me keep the budget down on the alltrac so i can focus on the RA over the winter.

You should be good.