Yep, I seen it at the track . My 408 at 11.3:1 would always slow down with anything but pump gas, i used 93. Many told me i need higher octane at the track with this combo. Vp told me 110 was needed at the track . Well guess what, they were all wrong and now many are finding out that 110 is way too much in a 11:1 motor . Mine my have ran better on 91. Some have said they run 93 pump with 12:1 compression. You just need to keep an eye on things like plugs for instance. My 511 may have ran better that 10.40 if I had ran straight pump 93 in it as well