Originally Posted by JTBMW1
My only concern is that if you drive on it when it is fully deflated- from just a simple nail puncture- do you ruin the tire? And if not can the tire be repaired with a patch on the inside? The cost for this is typically 50 bucks. So if you can drive on it "flat" then repair it, I am fine.
If you do ruin the tire and have to replace it and especially if the tire on the other side is 30% or more worn, they you may have to replace in pairs- which is very costly- then I have a concern.
If that is the case, then I may want to get a mini spare and keep it at home and throw it in the trunk for the long trips. Around town I would keep it out and if I get a flat call the other half to retrieve the spare in order to not drive on the run flat to save the tire. I just came from a Miata- which has no spare, no run flats. The car comes with sealant that when used ruins the tire and it must be replaced. To me, there was no value in using the sealant so, so I bought and kept a mini spare at home.
Yes, it will probably damage the tire making it unsafe to repair. But since most punctures result in a slow leak, I simply carry a small compressor in the trunk (with both RFTs and go-flats) in order to reinflate as necessary en route to a service facility.
The only benefit I see to giving up valuable trunk space for a doughnut spare is that simply having it makes a puncture less likely. But so far, just carrying the compressor and plug kit has warded them off for me.