NGK spark plugs are installed in all vehicle categories worldwide. From the original engine to racing, NGK is one of the top manufacturers of spark plugs. And it is important to install a high-quality and above all suitable spark plug, as the cost of engine damage is in no relation to the price of a good spark plug. The right heat value is the most important thing when choosing the spark plug. A candle that is too hot may cause engine damage and too cold can cause the candle to be constantly sooted. Therefore, it is important to always use the same heat value as that of the original candle with untuned engines. For sports and racing engines, it is advisable to use a slightly colder candle.