Yeah, I have had that happen to me as well. (That's why I stopped running BFG tires!) I have also started running Bias ply tires because they are stronger.
In a pinch, we have fixed a sidewall slice like that using zip ties, a tire patch and a lot of patch glue. Not the best, but it held for the rest of the wheeling trip!
*knock on wood* since I have started running bias tires, I have yet to have a tire failure. I am well set up to patch a tire if needed. My trailer runs a 6 on 5.5, so I can use that spare if I'm desperate and I am usually running with another Toyota if I need to borrow a spare.
That being said, I would always recommend running a spare tire and if I was doing something like expedition style wheeling, I would make room for one.
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