Largest spare tire that will fit in the carrier?

Seems like stock tire varies from van to van based on model/year, but 205/75-15 seems common. Anyone fitted anything larger than that in the underside carrier? The spare that came with my van is pretty old and if I replace it, I'd like to fit something larger, if possible. I know my current 235/75-15s won't fit (found that out the hard way)

Keep an eye on the load rating of anything you get, these vans are rather heavy when fitted with all our extras!

Bumping this thread to see if anyone has experience storing a larger diameter tire (and how large) in the carrier, or modifying the carrier to fit a larger tire.

I've abandoned my spare - so much smaller than my currently fitted wheels (20" 235/70) I figured it was useless. What are your thoughts on a spare that is smaller than the other wheels. I carry Holt's Tyreweld (medium size) but not sure whether that would actually get me out of trouble. My breakdown service specifies that I should have some means to deal with a flat tyre. So far I haven't strayed that far off the beaten track. I wonder whether there is some way to fit a spare to my towbar.

I think for the part-time 4x4 vans, temporarily running a different sized spare (to get you home or to the tire store) isn't a bad thing, as long as you don't have an LSD. I'm not sure if you are supposed to do this on the full-time 4wd models though.