If you believe NGK marketing of their Iridium plugs...Originally posted by eclipsed4utoo@Nov 23 2005, 11:21 PM
you won't gain performance from changing spark plugs persay.Â* lets say you go 60k on a set of plugs.Â* over this time, lets say you have lost 6hp from the plugs getting old.Â* when you replace the plugs, you will get that 6hp back.Â* so you will get back anything that you have lost, but you won't "gain" anything from the "high" performance spark plugs.
[snapback]36356[/snapback]
http://www.ngkspark.com.au/feature_index.htm
Plenty is said about delivering more power, in addition to the already stated longevity gains.