ORIGINAL: RoswellGrey

On the issue of fuel, when I bought my 2000 Mustang with its powerful V-6, the salesman said NOT to use more than regular grade fuel because anything more would screw up the platinum-tipped sparkplugs. Wouldn't a modern, high-performance engine like R/T has ALSO use platinum-tipped sparkplugs? Hence, wouldn't anything other than regular grade gas screw them up too?