New NGK BUR7EQ / BUR9EQ Spark Plugs

[Rotary Evolution]

i have not noticed any change in the plugs, some new ones are boxed in a silver package but they look the same physically compared to the old yellow boxed versions.

i use R6725-105 leading/BUR9EQ trailings for anything over 350whp. the BUR9EQs are fine for anything below that. yes i also realize this goes against the thought process that the trailing plug should be colder than the leading, but of course with anything testing told me that it was a waste paying $50 for upgraded trailing plugs, same goes for ignition amps to bump up trailing output. trailing ignition is just a placebo, as long as it is firing consistently it will still bring in the numbers.