my car idled the same with either plugs. i just went 9's because it *should* aid in performance

 

My car fouled out the 9s in a matter of about 200 miles. No big deal. I maybe drive the car 50 miles a month. But the sad part is, I have a HI-6 on my car. But, that does'nt keep me from putting 9s back in though!

Plugs are cheap, motors are'nt.

BTW: The reason it fouls plugs is because I'm running my own anit-detination device. 9-1 a/f ratio. CJ

 

9s....any added insurance against detonation/pre-ignition is well worth it

I've never had a problem and I usually get 15k out of them, the insulators always look nice and brown

ok, that didn't sound quite right

seriously though, if the plugs load up, YOU KNOW WHAT TO DO....my car is hardly ever below 4k

 

i had problem of hard starting using 9's so im putting the stocker back... im in the 3 mod rule area maybe that's y??

can any1 point me to a right direction, which one is Trailing 1 and Leading 1?? dont want to get mixed up and blow me engine... tanx

 

7s are leading if that is what u wanted to know

 

front rotor, bottom is leading 1
front rotot, top is training 1

Tim

 

9 all around no problem. Hot conditions like Athens , Cali , Florida .........

 

That's the answer im looking for!!! tanx Tim

Damian... 7's at the bottom and 9's on top... got it...

Sevenin7: i live in a tropical country and i use Trust Greddy Racing Pro Plugs, all 9's... but somehow its just hard to start!?! dont know what the problem is... i crank and crank and then it start. On a hot day its even worst... any1 experience this?? or maybe its not related to the plugs?

 

i'm in the mountains in utah. been runnin 9's for years. i had all the bolt-ons, til my motor went. i've never had problems starting, or rough idle either. aws disconnected. i recommend them also.
shaun

 

man, my simple question turned into an awsome reference thread on plugs, thansk guys!!!

 

Mazda put the 7's in for emisions purposes only. I run all 9's and have had no problems.