Quote:
The concrete benefit of the double-platinums is that they last practically forever... 10 years or 100,000 miles is not uncommon.

But non-platinum plugs can give a big fat spark too. Just need a good ignition system and large gapping.

The thermostat controls the coolant temp -- but not combustion temperatures. Timing has effect on combustion temps. Plug heat range controls the temp of the spark plug itself.