using plugs to get that same effect is not reliable... you should use the plug that your engine in combination with your fuel likes , some engines are happier with colder plugs then others , i know my STS 21T can't stand cold plugs , even with 30% it has a hard time starting, however go to a hot plug or a medium/hot plug and it will be fine...

now on the other hand my buddies 8ight who runs a Axe rossi engine with a turbo head , he runs cold or medium/cold plugs with 30%..