Nope, i didn't feel any difference between misfiring and non misfiring. I did notice that the Fuel Consumption needle, (@ Odometer) the needle was always moving in the 15l/100km range to max range when driving at low speeds. It appears now it's at the 10l/100km and sometimes lower. I am now getting 10km/l. Basically mostly highways. Per day maybe 80km run...of this 80km's..50km is highway. No slow traffic. Previously on this similar route i was doing 7km/l. On side note may go for this Kcarbon thingy when i stop over at KL on my next trip.