stock? My car is just NA, no SC or NOS. I'm going to have my plugs changed today or tomorrow.

Thanks

Blade

 

Blade,

Read this post:

http://forums.maxima.org/showthread....threadid=45742

Look under the "Spark Plug" post. There is a link that helps explain the heat range differences.

 

Heh heh...

Ask MedicSonic, he has dyno numbers and 1/4 mile times that will let you know just how much performance you can expect.

 

I wouldn't do it unless your car is REALLY driven hard or for very long distances. I noticed a rather large decrease in performance when I put the colder plugs in (the car was noticably less 'enthusiastic' to go), and yes, I did make sure that they had the right gap and that they were installed correctly. When I changed back to the 'regular' heat range, the performance came right back. This was with absolutely no other changes in the car between the differences, so I HAVE to blame the plugs. Some dealerships supply both the regular ones and the cold ones and will install the colder ones if you don't pay attention (cough***Premium Nissan of New Rochelle, NY***cough), so make sure that they are the right ones.

 

is there a way i can tell if i have colder runs spark plugs because i have had my service and i lost performance. my max is slow

 

Pull out the spark plugs and look at the part # printed on it.

 

my parts buddy told me today at the dealership that the NGK's 5 range and the 6 range are the same exact plug.. no diffrence.. he even showed me the refference number on the plug.. they were both the same.. so now i am confused

 

Then why would they have different numbers? Check out www.ngk.com, they list the PFR5G-11 as the OEM plug, the PFR6G-11 is a cloder plug. For more info on plugs and heat ranges, go to http://www.ngksparkplugs.com/techinf...s/overview.asp

 

That's interesting. A few months ago when I got my spark plugs from Courtesy Nissan, they had the "6" listed as the OEM replacement and that's the one I got. I don't notice any performance loss or startup problems, unlike the Bosch Platinums I had in there for 4-5 months which sometimes took a few cranks.

 

Yeah, Medic lost bigtime torque with colder plugs.

 

All this talk made me go out and sample one of my plugs. From what I gather from the NGK website, too cold a plug may result in an oily residue or even fouling. In my case, the PFR6G-11 plug looked perfect, not oily at all. Don't know if the appearance correlates to performance but at least it probably indicates normal operation. Interestingly, before I even knew what to look for in spark plug appearance, I remember the Bosch plugs that I took out were definitely oily--though not fouled.

 

Take a look at this site, {url]http://hammer.prohosting.com/~98fxdwg/plugs.htm[/url]

You'll see what you don't want your plugs to look like.