Without any mechanical modifications to the engine, the extra power you gain will be about 10% at the most, after being properly tuned. You can achieve similar results by having the factory ecu professionally tuned for performance, but if your engine factory ECU is damaged or there is no other tuning solution available a FuelTech ECU will be a good option. The benefits of a FuelTech ECU become extremely valuable when you add boost to a N/A engine, add nitrous or have a highly modified engine. It also adds data logging and built in racing and high performance features that can help you out on getting the most out of your combo.