I don't know the exact depth Nissan says, but they don't recommend going deeper than the hubs.

I've been in water that has completely covered my 32.7" tires several times and haven't had any problems, other than a wet horn and water in my foglights (which has yet to affect their performace, even when I've left them on when they are under water).

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Michael Girardo
Member - MAXC | Moderator - XOC
www.avaloninternet.net/users/bythebay/xterra <---Redesigned