Miss with 87 octane but not 89
 

Hi all. I've been trying to figure out a missing problem I have had for quite a while now. I have finally figured out that it only happens when I run 87 octane. It doesn't knock or anything like that. Just misses when under a load, like cruising in overdrive and pressing the gas but not enough to downshift, or if I floor it it falls on it's face in the high RPM's. Normal driving it is fine. 89 octane everything is fine all of the time. Any ideas? Thanks!

Are you buying a premium brand like Chevron or Shell or are you just buying the cheapest gas around town?

I pretty much always use BP.