I ran the OEM platinum plugs until the last change and decided to try iridium...

my fuel economy is a little less than with the platinums (and yes I gapped them correctly)

who knows. and to add...ive actually started driving slower since I'm half a millimeter off the ground

 

Typically for every 50hp to 75hp increase in power over stock, you should run a step colder plug, or if you live in a hot environment, or if you do a lot of racing with the motor in the rpm range. Here's a great write-up about spark plugs:

http://www.carcraft.com/techarticles...ips/index.html

 

^ Thanks for the link

Should I run the One step colder plugs? Engine is nearly 100% OEM it has its timing advanced +2. I do live in south Florida were its hot most of the time.

But since my engine is stock I am looking at stock plugs heh.

Service Manual says
I drive 62 miles highway every time I go to school, which will be 4 times a week in Aug, But I dont know if that counts for extended.
And I redline it sometimes like everyone else

 

^Don't lie, you drive like an old man

 

^ lol sometimes

so is that a yay for colder plugs?

 

I use 1 step colder NGK copper. But between the 2 listed there, I'd use the Iridiums. Te platinum are just awful all around I feel. For DD cars, it's fine, but anyone who is modding a car in anyway should pull them out ASAP. platinum is not a good conductor and gets really hot, pre-ignition hot way too soon with any performance mods to the car. I had the platinum actually melt off the plug in 2 cylinders and get welded to the cylinder I think. (hope they are on the cylinder at least) just my $0.02

 

If you are stock you really shouldn't drop down to a lower heat range unless you are getting "spark knock" under normal conditions. It really shouldn't hurt much if you do but if you are not in the proper heat range you may not burn off the excess buildup on the insulator properly.

 

How about Denso Iridium vs NGK Iridium?

 

Not much of a difference - but I stick with NGK for all japanese made vehicles by nature. japan knows japan. its like Bo knows Baseball Bo knows Football. You can't argue with that kind of logic.

 

Denso is a Japanese company, I'm not sure about NGK...

 

Personally, I've been buying Iridiums (one step closer) pre-gapped from injected performance every year. I think our stock plugs are iridium no?

 

^Usually they're platinum. Mine were.
I think they may have changed to iridium later, but I don't know when.

 

I like to clarify that I have no idea what "one step closer" means. I meant one step colder :O

 

+1 I agree with keeping the factory gear, if you are running everything OEM then you why look for a replacement. Theres alot of hype over things that make miniscule of a difference. IMO.

 

Excellent thread. Ashley, 8 months on how are the spark plugs treating you?