Re: Flat Tire...Is it okay to run 1 new tire with 3 old ones?
If the difference in diameter is too much, you could have some lights on the dash come on. The ABS will be confused by the tires rotating at different speeds. If you don't get any lights, you should be fine running the newer spare. A tire shop will probably be able to take you tire off the wheel and put a patch on the inside. It should be good enough to use as a spare that way.
2007 - Titanium, 6 MT, Locker/A-Trac, TRD exhaust, Trail Gear Sliders, Ricochet Skids, Metal-Tech Bumper, Bilstein 5100s on 3rd notch, Warn 9.5ti, BFG ATs 285/70/17, ToyOutfitters LCAs