You wont waste more gas because of bigger injectors. Thats a myth. Bigger injectors only mean bigger potential. Injectors only spray what you tune them to spray. You could puy 1000cc inj on a 120hp honda i wouldnt make a difference. It be stupid though. Figure out what hp youre shooting for and buy inj accordingly. Always buy slightly bigger inj than what you need. Z1 has a good inj selection check with them.