Using this product our team found that our automotive engine now runs smoother and has improved gas mileage.The Autolite XP5364 Iridium Spark Plug provides sturdy and efficient spark, making our car start up SEAMLESSLY every time. The only downside is that the price is slightly higher than other plugs, but the superior performance more than makes up for the cost. Overall, we`re thrilled with this ignition part and highly recommend it to anyone in need of a reliable, durable spark plug..See full review