Originally Posted by mobilefitt

I had a buddy split his plugs up in the engine, One colder/one stock One colder/ one stock.... but he did not have 2 plugs per cylinder. His car ran and sounded amazing. It was a Toyota and he did it accidently. He went to buy a stage colder plug and only had money for a few so he kept a few stock and changed a few.

Has anyone tried plugs a step colder in the N/A car? I think that there is potential for more complete fuel burn in our cars having 2 plugs per cylinder. Having one cold, one stock, would give fuel 2 environments for combustion. ( This could work or it could be a disaster).

Any insight on the NA configuration and plug temp would be appreciated.