Installing a hotter heat range plug will reduce the pre-ignition safety margin, so it is better to correct the mechanical or tuning issue instead of changing the plug heat range. What does the heat range really mean on your spark plug? We have the answers on our training resource page.

Autolite has 2544, 2545 and 2546 available. 2544 is the coldest plug in that plug family, and 2546 is the hotest. However, according to an Autolite reference chart, Autolite 86 has the same heat range as 2244 and Autolite 303 is a hotter plug than 2974.

What is a Spark Plugs Heat Range? The term heat range refers to the speed with which a plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be …

The heat range of a spark plug is the range in which the plug works well thermally. The heat rating of each NGK spark plug is indicated by a number; lower numbers indicate a hotter type, higher numbers indicate a colder type.

Selecting an optimal heat range for NGK spark plugs has many benefits, such as improved fuel economy, stable idle, and more complete combustion cycles, resulting in greater power output from your engine overall!

Use the Heat Range Conversion Chart to compare the heat ranges between spark plug brands. Use NGK's Numbering Systems to decipher NGK's alphanumeric part system. A numbering system is also available for NGK spark plug resistor caps.

Dec 29, 2014 · Heat Range Reference. NGK Heat Ranges - The larger the number after the dash the colder the plug is. Example a R5671A-7 (a good street/strip plug) is a cold plug where a R5671A-10 is a very cold plug used for large 400hp and …

Typically the heat range for NGK Spark Plugs varies from 2-11. This number indicates the thermal characteristics of a spark plug, or how ‘hot’ or ‘cold’ a spark plug is. The term hot/cold is commonly used to describe whether a spark plug heats up easily (hot) or whether it provides resistance to heating up (cold).

NGK indicates the heat range in the middle of the plug number. For example, BCPR6ES-11 has a heat range of 6. (The number after the “-“ is the gap.) NGK plugs are colder the higher the number, hotter the lower the number.

Using a spark plug in the correct temperature range ensures the best performance in your engine. Learn other DIY repair tips on our resource page.