This from a professional tuner specializing in Chevys. What do you guys think? I’ve never heard this.
I used to use it myself in my monte carlo SS… then after doing some data logging of my own car, I noticed a ton of knock retard… so I switched to Mobil 93, and it all virtually disappeared… and the thousands of tunes I’ve done for people, I can normally tell if they’re using Shell gas as well, due to all the knock retard in their logs… I’ll ask them about it, and they’re like - how did you know I was using shell!!! haha… so yep, I see it time and time again, shell gas causes knock retard issues… whatever additives they put in their fuel, causes issues… best to use mobil, exxon, sunoco, bp, chevron… mobil/exxon being the best to use…