Review on Champion RC12LYC 412 Copper Replacement by Raul Fabijan

Don't buy fancy platinum spark plugs for your Jeep 4.0. Look at the gap on them, .035 platinum irriduim or something else where the gap is much larger. It stresses the coil cover and rotor and corrodes the cover and rotor, resulting in lousy idling and stalling at higher RPMs. Buy these and a cap with brass connectors and 8.2mm cutting wires and you'll have a chain that will last a long time. A 3/4 turn after contact with the head will crush the washer. A torque wrench is not required. Taylor wires are thick enough that you don't have to use stupid weird factory routers. If you use normal gauge cable without a router, the spark jumps over and it works lousy. And change the fuel filter at the same time. If you discard Taylor wires, test the resistance on a new set of wires. It will probably be worse than your originals! And regular 10w30 oil, not synthetic or rear oil, starts leaking and never stops! Great connectors but expensive for copper connectors and also without electrode protection so you have to bend it back. At least 2 in each shipment the electrode broke due to handling or something else.