well, i drove around on it all weekend, probably put about 300 miles on it.
this morning i was able to find a shop that had a potenza RE760 non-runflat tire in the right size so i had them mount it up. i was going to try to drive back from buffalo with the donut, but was a little wary of driving non stop at highway speeds on it. 147 for the tire, and i got a front sized tire (i had blown a rear) so i can use it as a spare front or rear.
the donut spare worked admirably, as long as you kept in mind that it was a donut and drove more conservatively. ended up visiting all the places i was going to, minimal interruption to my trip, and it held me over untill i could find a suitable tire. most of the trips were short, in town trips, a few 30-50 mile ones though
interestingly, the dealer i got the tire from, even though it was a runflat certified bridgestone
shop, didnt have either the 225/40 or the 255/35 runflat in stock.
i dont think the runflat tire would have gotten me through the weekend with all the driving i did.