Maybe I just share my experience. I feed my fish with Mobil
5000. Have tried 2000, 8000 and v-power, all fall below my fc
expectation. I follow the manual instruction, basically it's 1st
gear to 20km/h max, 2nd gear to 30km/h, 3rd gear to 50km/h, 4th
gear to 70km/h and go easy on 5th gear for cruising. Though I am
always rushing, I do not drive exceeding 95km/h till now. I also
have this habit of putting to neutral on down slope and couple
hundred metres before stopping. As i mentioned earlier, I wish my
fish could pick up speed a little quicker though...