Champion Spark plug number decoding

[97MACHZ]

Does anyone know the formula for decoding Champion spark plug numbers/letters. I would like to know the difference between plugs recommended for sustained high speed use and sustained low speed use.<br />Cheers<br />Mike

 

[Paul Moir]

Re: Champion Spark plug number decoding

Usually it's the heat range. Hotter plug for low speed use to burn off deposits. Too hot and you'll get pre-ignition, which will put holes in yer pistons.<br />

<br /><br />With Champion plugs, the higher the number, the hotter the plug. Almost all the others work the opposite.

 

[97MACHZ]

Re: Champion Spark plug number decoding

Thanks very much for the great info.<br />Cheers <br />Mike