I have been caught on 87 octane without any onboard NOS booster, limped along for a few hours without any high rpm runs nor overgeared lugging and had no problems. No detectable pinging, dyno runs/ 1/4 mile passes after and no issues to speak of. Small side benefit of a low compression motor perhaps. Otherwise I live on Suncoco 94.
Oh, the best part, when limping on the 87 up near Grand Bend, Ontario, what comes flying up beside me, passes me and wants to run, a Yellow Z06. True story......ugh. I just shook my head, surely he told his family over dindin about the Viper guy that was scared to race!!