Spark Plug Heat Range: What It Is and Why It Matters

Spark Plug Heat Range: What It Is and Why It Matters

Bottom line: The heat range tells you how hot a spark plug runs and picking the right one keeps your engine clean and running smooth.

Design & Looks (Heat‑Range Basics)

Every spark plug has a “heat range” printed on it. Think of it like a thermostat for the plug’s tip. A “hot” plug stays hotter longer, while a “cold” plug cools faster. The right balance stops fouling (when carbon builds up) and avoids overheating that can melt the electrode.

Performance & Mileage (How Heat Affects Power)

When the plug runs too hot, the spark can pre‑ignite the air‑fuel mix, causing knock and lower mileage. Too cold, and the plug can misfire, wasting fuel and hurting performance. Matching the heat range to your engine’s load, temperature, and fuel type lets you extract the best power without sacrificing efficiency.

Price & Rivals (Choosing the Right Plug)

Most drivers won’t need a custom‑ordered plug. A reputable brand’s medium‑heat plug works for everyday street use. High‑performance cars often benefit from a colder range, especially if you run higher boost or aggressive timing. Prices range from $5 to $15, so the cost is modest compared to the savings in fuel and engine life.

FAQ

What is spark plug heat range?

The heat range indicates how quickly the plug’s tip dissipates heat. A higher number means a hotter plug; a lower number means a colder plug.

How do I know which heat range is right for my car?

Check the owner’s manual or the OEM part number. If you drive hard or live in a hot climate, a colder plug is safer. For normal street driving, a medium range is usually best.

Can using the wrong heat range damage my engine?

Yes. A plug that’s too hot can cause pre‑ignition, while one that’s too cold can foul quickly, both leading to reduced performance and potential engine wear.

Got a plug story? Share your thoughts in the comments below.

Source: Read Official News