Plugs

[rbriggs665]

I've got a 2003 Grand Prix GT 3.8 non supercharged engine. Anyone have a recommendation for spark plugs. When i replaced the ACDelco Rapid Fires with NGK I lost a mile per gallon. Will I get the best mileage with the Rapid Fires, Platinum, or Iridium plugs. Is ACDelco the best for a Grand Prix. I've been told to stick with American plugs for an American car. Suggestions?

[SlowNA06]

1. Country doesn't matter. How does that seem to be a scientific rule?
2. Don't use platinum. Ever.
3. I doubt your 1mpg is from spark plugs, if it is more than a figment of the imagination.

Use ACDelco, NGK, or AutoLite iridium spark plugs in the stock heat range.

[rbriggs665]

Thanks Slow - that helps!