Question: are e3 spark plugs any good?
Answer: Here are some excellent features that make the E3 Spark Plugs one of the top-rated spark plugs on the market: ... Depending upon the engine class, the E3 Spark Plug improves the engine power by 6% to 12%. Again, depending upon the engine class, the E3 Spark Plug enhances the fuel efficiency by 4% to 13%.