Going with a colder spark plug?

[4PASNU]

I've done some searching on the forum on websites and can't find any information on going to a colder plug.  I did the plug selector on NGK web site and it says the TGP uses a part number 2238 for the TR5 plug.  So what if I want to put a plug in that is one heat range colder.  What would the part number be for that?  Has anyone done this?  Is it recommended for the TGP?

[eclipse5302]

I looked for a colder plug when I was playing around with high boost/extra fuel a while ago.  Apparently, the TGP uses the coldest plug available already.  At least it's the coldest plug GM and NGK offer.  Even if you could, I really doubt you'd need to go any colder though...

Jason

[4PASNU]

OK, well I contacted NGK about this colder plug issue and here is what they responded with (my question is below the response).  

Use a TR6 stock number 4177.

Jon MacQuarrie
Technical Customer Service Representative
jmacquarrie@ngksparkplugs.com


-----Original Message-----
From: webfeedback@ngksparkplugs.net [mailto:webfeedback@ngksparkplugs.net]
Sent: Saturday, March 29, 2003 1:48 AM
To: info@ngksparkplugs.com
Subject: Tech Info Feedback


VehicleType: Car

Make: Pontiac
Model: Turbo Grand Prix
Year: 1989
Engine Type: 3.1L 6cyl Turbo
Comments: I used your part finder and it came up with TR5 part number
2238.  My question, if I want to go one heat range colder what part number
do I use?
When: 3/29/2003 1:47:39 AM
Used Part Finder: 0

I think I'm going to order a set and see how they work.   :D

[Mr. Mod Man]

What is the gap?


NGK Iridiums?

[4PASNU]

I think the gap is set at .045 from the company but as with any plug you can set it to whatever you want.  
I think they are the V-Power and not the Iridium.  Not sure on that one though.

[Mr. Mod Man]

actually Ngk Iridiums are pre gapped and it is not recommended that you change the gap either (thats what it says on the box) Thats not to say you don't check the gap.