I have 6.4L srt and I have several mods including tune hemifever, CAI, high flow cats and long tubes, mid muffler delete, Ported TB true by fastman, and 180 thermo. I recently added Lucas Octane booster to my Shell 93 octane (with up to 10% ethanol) and I will tell you what talk about a difference. I read many reviews about how Lucas is the only legitimate one to use and raises octane by 3 true points. So I'm running 96 at this point. My car literally feels like 30 more HP easily and zero knock now according to tuner data. Anyone else run this stuff all the time? I found a website where you can buy it for $5.68 for 15 oz which treats up to 25 gallons. I'm all for putting it in every tank for my car to run this clean feeling and have that much more torque and power. Stinks we can't buy 96 octane here in Austin TX or 100 octane race gas. Looks like Keileen tx is closest station that has it. Way too far for me.