"Jim Kelly" wrote in message
...
I am questioning your assertion that "combustion is strictly the pervue
of how hot the spark is." I contend that that it is necessary to
increase the fuel to air ratio on a cold engine because the engine is not
imparting enough heat to the mix to create a combustible mix regardless
of the heat range of the plug. Therefore, engine temperature has a
direct effect on combustion.

You have the right idea. The spark delivered to the combustion chamber is
the same regadless of the plugs heat range. The only way to get a hotter
spark is if you use a hotter coil. And using a hotter plug than the
manufacturer recommends is can damage the engine. You will always need a
richer mixture in a cold engine, the fuel doesn't atomize as well when cold.
I installed an aftermarket programable fuel injection in my truck. It takes
30-40% more fuel for cold starts.

Rich