Will Changing Spark Plugs from Heat Range 7 to 6 Increase Urban Fuel Consumption?
3 Answers
When the air-fuel mixture experiences incomplete combustion, you may notice that under the same fuel consumption conditions, the power output is not as good as before. Here are detailed explanations about spark plugs: 1. Introduction: The spark plug is a crucial component in the ignition system of a gasoline engine. It introduces high voltage into the combustion chamber and generates a spark by jumping across the electrode gap, thereby igniting the combustible mixture in the cylinder. It mainly consists of a terminal nut, insulator, terminal stud, center electrode, side electrode, and shell, with the side electrode welded to the shell. 2. Heat Range: The selection of a spark plug's heat range can be based on the engine's compression ratio, speed, and air-fuel ratio. Commercially available spark plugs have heat ranges from 5 to 13. The higher the value, the 'cooler' the spark plug, known as a cold type, which is suitable for high-compression engines. Conversely, the lower the value, the 'hotter' the spark plug, known as a hot type, which is suitable for low-compression engines.
I've been driving for nearly twenty years, mostly in the city. When I changed the spark plug heat range from 7 to 6, the fuel consumption did increase significantly during heavy city traffic jams. This is because spark plugs with lower heat ranges dissipate heat more slowly, making the engine prone to overheating. Frequent starts in urban areas with low engine loads increase the risk of carbon buildup. When spark plugs don't ignite properly, incomplete combustion occurs, leading to higher fuel consumption. I once tried using the wrong spark plug model in my car and noticeably had to refuel more often. I recommend checking your vehicle's manual or consulting a repair shop first—don't make random modifications. Only when the spark plugs are correctly matched will your car perform well and save fuel. In short, be cautious with this modification to avoid potential issues.
I often commute short distances in the city, and recently I was curious and tried switching from spark plugs with a heat range of 7 to 6. As a result, I noticed increased fuel consumption, especially on routes with many traffic lights, and the engine sound became muffled. This is because with a lower heat range, the spark plugs dissipate heat less effectively, and combined with the significant temperature fluctuations of the engine during city driving, it can easily lead to unstable combustion, wasting fuel. After switching back to the original factory specifications, everything returned to normal. I believe any modifications should consider actual needs, such as engine type and driving habits. City driving is already more fuel-intensive; don't lose the big picture for small gains.
