Bosch spark plug deciphering

[C1J1Miller at aol.com]

Bosch says "...a low heat range number indicates a "cold plug" with low heat absorption through its short insulator nose.  A high heat-range code number applies to a "hot plug" with high heat absorption through it's long insulator nose"...
So, 2-4 is cold, 7-10 is hot...

why not stick with what the manufacturer lists?
Chris


Brady Moffatt writes:
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Hi All,

Is a 7 a hotter plugs than a 6 in Bosch-speak?

I was just at the NGK site www.ngk.com . In NGK-speak, a higher number is
colder (dissipates more heat).

Cheers,
Brady Moffatt
Montreal, Quebec, Canada
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