I don't worry about fuel , whats a couple of dollars a tank , but i have noticed that i get less mpg than i did , but i've also noticed more power in the lower gears , On long journeys sat on 110 klm i still get high 30's , overall though i'm probably down 30klm a tank , not enough to worry about, although to be honest , the extra power to me does'nt matter the r3t had all the power i could handle anyway .
Why did i change , dunno , cos i could i suppose .