Probably a dumb question, but so much of what I took for granted with other vehicles I've owned is different with the Disco...

I put General Grabber AT2 255/70/R16 tires on my truck. The spare is still a Michelin (can't remember which model?)255/65R16. Pretty minor difference in size between the spare and the Grabbers; obviously a significant difference in tread.

Is keeping this spare good enough to get me to help if I blow a tire (on or off road), or do I need to replace itwith with a Grabber? I intend to replace it with the Grabber at some point regardless, but would rather not spend the money on it right now--unless using the current spare in an emergency would somehow screw up my truck.

 

I wouldn't have a problemusing it as a spare.

 

You are fine.

 

Could be wrong, but not so sure the full time 4wd andtraction control would love that too much. I would not attempt it. But to find out, Since 255/70 are a full inch bigger than a 255/65 , deflate 1 of your tires to make it 1/2 inch lower than the other one and you'll see.

 

Darover is right, the TC and such wouldnt like it, but you will not hurt anything. It is a spare tire, not a replacement tire. It is meant to get you home safely and nothing more.
Now if it were a 15" tire that would be a different story.

 

When you turn, one wheel needs to turn faster than the other. This seems like the same situation. Now if you had a locking differential, that would be a big problem. I'm no expert on traction control, but as far as I know it senses if one wheel spins and uses the brake to lock it, sending power to the opposite wheel. I believe the key word is 'spins' though. If the TC kicked on when one wheel just 'turned faster' than the other than I'm not sure how you would turn. It may handle funny, but as a short term spare I'd think it would be ok, then again I've never done it.

 

When I got my 94 Disco 1, I drove it on a 500 mile trip with the tires that came on it, and later discovered that one tire on the rear was a different size. I did notice that the truck wanted to drift in one direction on the highway. I replaced the rear tires as a pair, and now the truck tracks straight. I did not notice any driveline stress from running the mismatched tires, and I think a spare that is relatively close in size to the mounted tires should be OK in a pinch, as long as you don't engage the lock up. After all, a brand new spare is going to be a different size than mounted tires, as it won't have the same tire wear that the mounted tires have,.unless you rotate it into one of the mounted tires as part of your tire rotation routine.