Injector size doesn't matter, in the tuning process you change the injector pulse width to whatever is needed to keep the proper air fuel ratio at a certain rpm and engine load. This chip is not for you if you have never tuned a car before unless you are going to pay someone to tune it for you which gets expensive. This is not a pre-programmed chip, you can download 2 tunes from the miller website, but that is not what you buy this chip for, you buy it if you are changing major items on the car and the stock and performance chips wont control it. If you just want a little more power, say you have an intake and an exhaust, then get a Mark D chip. If you are going to boost your car, ITB, big cams, extensive internal engine modifications, alternate fuels (alcohol, e85, etc...) then this is the chip for you. It really shouldn't even be called a chip, it is a circuit board that completely replaces your stock eprom chip.