been using Petronas RON95 since engine swap process finished. sometimes fill up Shell RON95 in case of emergency. In comparison, very little difference shown. For mileage, of course Shell is better off by 3-5kms. So far, no knocking, no sluggishness, no nothing at all. 180km/h also no problem for both tank has got no hole, but pocket...err...yes. big holes here and there