Just was curious.....I have AC Delco R45TS's(i believe thats the right part #) gapped @ .035"ths in TA....with all the mods I have done(see sig), I was thinking to change them to a hotter plug. What would be the next hotter plug from what I have in there now? I'm just not sure how that numbering system works. Would it be worth it to run a hotter plug? Also, my car has never ran better than it runs on the regular AC Delcos....i've tried Bosch and the car runs like s*** on them.

 

What signs are there that the engine wants the hotter plug?.

A hotter plug puts you closer to the detonation threshold, and may push you past the threshold and into detonation.

An improper tune with too much timing, and too much fuel can generate the apprearance of needing a hotter plug, too.

 

There are no "signs" that it NEEDS a hotter plug. The car is tuned correctly right now, no piniging or detonation. The reason i asked was because i was under the impression that it would offer a slight performance advantage. Also, I've recently had a lot of trouble with the vehicle....code 33, and an extremely rich condition....however, all of that has been resolved thanks to my mechanic....he actually suggested a hotter plug, b/c it might help on startup to spark the combustion a bit easier.