Quote Originally Posted by rowhard View Post
Don't know, maybe someone here knows the answer to how much of a differential you can have to satisfy TOD 's needs without it going crazy.
Here's my own personal opinion/stance regarding the DONUT spare.

Using the DONUT spare tire for limited travel even with over-sized tires like the "LTZ" in 285/60R18 (31.4" O.D.) is still safe to use IN MY OPINION even with slightly larger tires, just as Marlin has pointed out in previous postings. The DONUT is 29.5" O.D. just like the OEM tires were.

The "key" is to only use the DONUT spare on the FRONT axle (never the rear axle), as the rear axle doesn't like mis-matched tires with TOD. Just remember to disengage 4WL whenever using the DONUT, so the VX will be in normal AWD (high range). I would assume the TOD system only likes 4 matching tires in 4WL mode, since it is locked in 50/50 distribution of power. If you've encountered a flat on the trail and your only spare is the DONUT, then your off-road excursions have come to an end for that day and you should be gingerly limping the VX slowly downhill back to civilization in normal AWD.

Heck; I run 32" O.D. tires (275/65R18), and currently my only spare is the DONUT. I'm not gonna' lug around a f/s spare 24/7 and constantly burn up $MPG$ with a air-drag resistant f/s spare on a roof rack when the DONUT will suffice in an emergency. You could even carry Two(2) DONUT spares (in case the first DONUT became a flat), than to carry one f/s heavy/bulky spare.

I do agree 100% with VX'ers who ONLY use a f/s spare while in an off-road environment. That is very wise and smart. If a flat is gonna' happen, it will most likely happen on the trail (not on the street). If I ever became a more avid hard-core off-roader; then yes, I would carry a f/s spare ONLY during those times. Just my 2-cents.