550cc Subaru Wrx / Sti Stainless Steel SS compatible with all fuels including oxygenated fuel with MTBE, FTW, Q16, M5, C45 SouthBay's "TruFlow" 550cc Fuel injectors maintain precise control of fuel delivery and atomization for more power better throttle response and improved fuel economy. Optimized in house and flow matched dynamically to within ±1%. Full data sheet provided with each set. EV-14, saturated High resistance. Extenders and pigtails for your installation included in the price along with flow data and dead times. High Impedance injector.