no

 

Unless you have Supercharger, Turbo, or Nitrous, you don't need a colder plug.

The colder plug doesn't even benefit powerwise for SC, Turbo, or Nitrous; it just helps protect your engine from detonation.

 

Some guys ping with bolt on's when they are N/A, california 91 octane sucks.

 

I know I have on NA alone before.

 

Did you try colder plugs? I'm sure it should help control detonation to a certain extent.

 

a colder plug just has the ability to transfer heat to the head faster and out of the plug. i am running 2 steps colder in my car. colder plugs can tend to foul at idle though from not carrying enough heat, luckily i have not had the problem with 2 steps colder iridium.

 

I have the IKH20 too. the idle went right up to 1k and the engine light came on, had to bring it to the dealer for adjustment. I gapped the plugs at 0.44, if they are really 2 step colder, should i re-gap them ?

 

are you n/a or f/i? might want to go a little smaller gap for f/i if pushing alot of power. if you are n/a, put the stock heat range back in.

 

Bringing a dead thread alive as it was very informative. Here are the part numbers for the rest of the Denso plugs:

Denso Iridium
IKH16------------------5343-------------Stock heat range
IKH20------------------5344-------------1 step colder
IKH22------------------5345-------------2 steps colder
IKH24------------------5346-------------3 steps colder
IKH27------------------5347-------------4 steps colder

 

Bottomline, Denso IKH16 or IKH20 for a 2003 G35 N/A in a hot enviroment? (70-90 degrees all the time)

 

bringing this one back from the dead....again!

mod list:
JWT Pop-charger
MREV2
5/16 Spacer
FI resonated test pipes
Motordyne XYZ pipe with resonator
exotic speed R1-T (3inch single)

Recently tuned with osiris and the tuner noticed right off the break that my car was pinging real bad when you would first stomp on the gas. He suggested that maybe I got bad gas but i have since then re-filled a few times at different stations and it is still doing it. Could it be suggested that maybe I should be using one step colder plugs?

 

In for response to this

 

so is it better to run platinum or Iridium?

 

I decided to replace plugs with the normal heat range stock plugs, switched from JWT to dry based filter (a'pexi), cleaned MAF and cleaned throttle body and the pinging appears to have gone away. But every once in a while I will hear it again right when I step on the gas but not nearly as bad as before...but yeah would still like to know about colder plugs on N/A setup such as mine.

 

x2
thisx2 more bump

 

It would be useless

 

so is it better to run platinum or Iridium?

 

it won't matter

 

It's like running after you ate a subway sandwich vs eating a burger. You'll perform the same.

 

oh ok.. thanks! i just want to get the best between the two