to say fuel oso same if tune good is ermm....depends alot on ur rite foot...if u can control ur rite foot properly and do the gearing right then yeah u can even save fuel (possible with DCNF, others i donno)...but if u keep flooring the pedal, it will definitely makan more than b4...
dats the nice thing bout DCNFs...it allows u to change ur driving style so can have ok fc (upshift gear earlier, downshift less, less pedal pressure to maintain speed)