@DrRocket: “The car makers did studies, and found that tire have become so reliable, many full sized spares were never used.”
I find that surprising. Even though I replace my tires before the treads get dangerously low, I get flats due to road debris about once every two years, which means the road hazard protection I get when I buy my tires always pays for itself. Whenever I get a flat and pull over to change it, I imagine that scene from the movie A Christmas Story when Ralphie uttered the f— word. If I didn’t have a spare, and had to wait for roadside assistance, I’d waste a lot of time waiting.
While I don’t keep any records regarding my history of flat tires, I would say that I most likely wind up with a puncture about once every 3-4 years. That is not very often, but–in truth–nobody can predict when a tire will start thumping and wind up flat. My next flat could be tomorrow, or it could be many years away.
That being said, I still want to have a spare tire, rather than a can of sealant and a pump. Even if I only have a donut spare, I am of the opinion that the donut is more likely to get me out of being stranded than a can of sealant and a pump–which would be useless in the event of sidewall damage.
Now that you mention it VDC, the last two flats I got were (1) I popped a bead (and wrecked a bearing and a wheel) on a nasty pothole in a parking lot and (2) I ripped a sidewall on a granite curb. Fix-a-flat would have been useless in both cases.
I’m an advocate of spares… full service spares. It isn’t such a big deal on hypercars, because they’re not daily drivers and not relied upon for transportation. But on regular cars I think it’s essential.