I want to get some iridiums for my engine since I'm due to change them. I watched bythabay video on changing the plugs and he suggested getting one step colder plugs. Can some one explain the benefit?

2003 coupe n/a intake and catback exhaust

 

Don't know if this helps much, but this is what the manual says:

 

cold plugs it is

 

Mine is due for a plug change too and I was considering the cold ones as well since I do a 70+ mile commute every day.

 

so i googled the cold heat range for us and i read alot stating that it's not a good choice for us unless we are modded. So, f--k it i'm going to use the regular. lol. although i do appreciate all the help. here's a link to them on ebay for $41
http://cgi.ebay.com/ebaymotors/6-New...s#ht_500wt_890

 

im running ngk iridiums at stock temp, you should be fine unless you have a fair amount of modding done. this was what my stock plugs looked like at about 52k



i think the the burning on the insulator was from the advance im running. the iridiums have cured my misfires and the engine revs much smoother now

 

Thanks for posting up that information. It helps alot cause I have a very slight misfire.

 

Who is running one-step colder heat range plugs around here? I was under the impression its mostly just the FI guys.

Any NA guys running these?

 

Unless you're running nitrous, FI, or other mods that greatly increase the compression of the engine, you don't need colder temp plugs.

The only reason to use colder plugs is that they lower thermal impedance and will run a bit cooler. In an engine that is running excessively hot, this will prevent "hot spots" from forming on the sharp points of the spark plug which can ignite fuel and create detonation (knocking)

If your engine is close to stock (with just the typical NA bolt on mods), you don't need them.

 

what mods would make it necessary for going to 1-step colder aside from FI?

I've got about every mod possible for NA without going into the motor (heads/rods/cams/etc)

What about Las Vegas/Phoenix and hot climates?

 

pull your plugs and take a look at them. burnt insulators are a sign that you need to upgrade your plugs

 

You dont need to do thos unless your FI. Its only to prevent detonation.

 

Well, its not only for FI. If you NA mods which really increase the compression or power of the engine, you will benefit just the same. However, unless your NA mods are adding more than 100hp power, you probably don't need them.

 

i'm wondering if in Phoenix, with the mods that I have, if they would have been beneficial...

 

Run the car hard in the heat while doing a cipher/autoenguinty etc data log on your ign. If there det, you should be seeing irregularities in the timing curves?