Which brand of spark plugs is better?
4 Answers
Spark plug brands that are considered better include Bosch, NGK, Denso, Suzuki, Three-dimensional, Makun, Kust, Honeywell, Autolite, etc. A spark plug is a crucial component in the ignition system of a gasoline engine. It introduces high voltage into the combustion chamber and causes a spark to jump across the electrode gap, thereby igniting the combustible air-fuel mixture in the cylinder. Under high voltage, the air between the center electrode and the side electrode of the spark plug rapidly ionizes, forming positively charged ions and negatively charged free electrons. When the voltage between the electrodes reaches a certain level, the number of ions and electrons in the gas increases like an avalanche, causing the air to lose its insulating properties. A discharge channel forms across the gap, resulting in a "breakdown" phenomenon. At this point, the gas becomes a luminous body, known as a "spark." Along with the heat and expansion, a "crackling" sound is also produced. The temperature of this electric spark can reach as high as 2000-3000°C, which is sufficient to ignite the air-fuel mixture in the cylinder's combustion chamber.
I've run an auto repair shop for ten years and have replaced at least a thousand sets of spark plugs. NGK and Bosch are the most reliable brands. Japanese cars like Toyota and Honda mostly use NGK as original equipment, while German cars such as Volkswagen and BMW often come with Bosch. Iridium spark plugs can last up to 80,000 kilometers, which is twice as durable as standard nickel alloy. Last time, I replaced a set of Denso double iridium spark plugs for a Civic owner, and he said the throttle response became noticeably quicker. Actually, Champion offers great value for money and is commonly used as original equipment for American brands like GM and Ford. Remember not to go for cheap no-name brands—once a customer brought their own unbranded product, and it caused a cylinder misfire within just two months.
Just replaced the spark plugs for my old Corolla after two weeks of research. For regular car owners, NGK is a safe bet with wide vehicle compatibility and the most availability at repair shops. If you're after performance, consider Japan's Denso – used in Lexus race cars, their ignition efficiency is truly superior, though prices are double. Iridium-platinum hybrids offer the best balance, like Bosch FR7NPP332W which lasts up to 100,000 km. DIYers should remember to check the gap – 0.8-1.0mm is ideal. Don't just focus on material marketing; heat range matching is more crucial. European cars typically need 7-9 heat range, while Japanese models require 5-7.
Experience in auto parts wholesale shows that the top three sellers are always NGK, Bosch, and Champion. NGK fits 90% of Japanese and Korean models, and its copper core effectively resists carbon buildup. Taxi drivers prefer Champion's OE series, which costs less than 30 yuan per piece and includes installation. In the modified car scene, Denso Iridium, especially the IK20 model, is popular, with performance car models specifically requesting it. Don't be fooled by packaging; the stamped serial number is more important than the brand. For NGK's BKR6EIX code, you can directly check the official website for specifications. Special models like Mazda's SkyActiv must use original specifications; random replacements may trigger the check engine light.
