Review on 🔥 NGK 4291 V-Power Spark Plug - ZFR6F-11, 4 Pack: Top-Quality Ignition Upgrade for Optimal Engine Performance by Rickey Ortega

I have used them on a 2002 Honda Civic LX (1.7L I-4) with great results. The owner of the car did not drive many kilometers on it, so there was no need to buy iridium tips three times more expensive. Although they don't last 100,000 miles, they are actually the equivalent copper core connectors. This means they have the same thread size and heat range. The NGK website has an excellent spark plug decoder to understand the nomenclature of their names. In the short term, you won't notice any difference between these copper and iridium connectors. NGK is OEM for many manufacturers and I've always had good luck with their spark plugs. While never the cheapest, they have always been reliable and kept the engine running as it should (no misfires). I personally stick with NGK because they are the OEM for every car I own (VW, Suzuki, KTM).