Ford Expedition 2018-2021 3.5L Gas Engine Iridium Spark Plug Set Power your Ford Expedition with this heavy-duty 6-pack iridium spark plug set, engineered for 2018-2021 models featuring the robust 3.5L gas engine. Iridium construction delivers superior heat resistance and extended service life, critical for maintaining consistent performance in larger displacement engines. These plugs feature optimized electrode geometry to maximize spark efficiency across all RPM ranges, enhancing throttle response and towing capability. The precise gap specifications ensure reliable ignition under demanding conditions, whether cruising highways or hauling loads. Complete engine coverage in one convenient package eliminates multiple purchases. Direct-fit design guarantees seamless installation with no modifications needed.