I timed the 20-80mph acceleration on my vehicle with 87, 91, and 93 octane. Then I put the SRA intake on it. This is dyno proven 10whp. With 91 octane and the SRA, it was SLIGHTLY quicker than with 93 octane and OEM intake. With the 87 octane, it was slower than the 91 by a larger margin than 91 was the 93. Proportionately, all the #'s stacked exactly with 10whp for the SRA proven by Corksport, and 87/227 and 93/250 and 91/242. Had a bit to drink, so figure it out. Sorry it's jumbled.I agree with the other posters in assuming that its around 242 with 91. I only have 91 available to me, and there is a perceptible difference in power between 87 and 91 once you get into the higher RPM range. I don't have any data to back my claim, all I can say is that I can notice it, so take that for what it's worth.