How to Choose Between High-impedance and Low-impedance Injectors?

How to Choose Between High-impedance and Low-impedance Injectors?

It is easier to determine the type of injector your car uses than you think. All it takes is to measure and review the impedance of OEM injectors and then select injectors that perfectly match your impedance. But failure to follow this basic rule means the risk of damaging your vehicle's ECU.

While several aftermarket ECUs can support low and high impedance injectors, you should select parts with proper documentation and verify their system support and added capabilities.

High impedance or saturated fuel injectors can send 11-12 amps current. A low amp lowers the injector's temperature, making it highly reliable. It is one of the main reasons high impedance injector design is more widely used for OEM applications.  

On the flip side, peak-and-hold or low impedance injectors send a more robust electrical signal that reaches 56 amps. But after the injector is open, the electrical signal can reduce to 23 amps. Although this type of design closes and opens quickly, it gets hotter in a short time. In layman’s terms, fuel injectors with a flow of current over 70 lb an hour are low impedance.

For the sake of context, the injector you need for a specific application can vary and depends on power levels and ECUs. For instance, if the high demand for fuel propels you to use low impedance injectors based on an ECU that was supposed to be used for high impedance, then you will have to run separate resistors to balance out the different current levels and demands.

INAT Auto Parts specializes in high quality car fuel injectors for car upgrades for more than ten years, including 1000cc car fuel injectors, 1250cc car fuel injectors, 1300cc car fuel injectors, and so on. They are E85 available and can effectively improve automobile power. Find more auto parts just at


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