NGK Iridium plugs

[RotemXB9]

Hello there guys,
Im interesting to install new plugs on my XB9SX 2008 euro model , Iridium ones, and Iv'e been checked on an NGK book that the number of the plug is DCPR9EIX until 2007 model with no indication for the 2008 model , and on the other hand the NGK webside got DCPR8EIX insted, for models 2005-2010
I live in the middle east where its pretty hot in here, shuold I install an DCPR8EIX or DCPR9EIX whice is "cooler" for the engine ?[confused]

 

[Cosworth]

The 8 plug is a cooler plug, most run the DCPR9EIX. The one step cooler plug isnt going to make a difference in opertating temps.

 

[konarider94]

The 9 will run a little cooler. A lot of people swear by it. I run the stock 8 heat range without any issues but I live in a much cooler climate than the middle east.

 

[Cosworth]

Yea I got it backward sorry, 9 is a cooler plug. Its not going to make that big of a difference. Only time ive ever seen a plug temp range be critical is in forced induction setups.

 

[WIGGLE2]

There are a lot of threads on here regarding this. You can search it if this reply is not enough. Contrary to every other plug manufacturer, the '9" is COLDER than the "8". NGK is the only one like this that I know of. Usually, the higher the number, the HOTTER the plug. It comes down to your riding style more than ambient temperatures. If you start the engine, make short trips, then shut it down frequently, or do a lot of low rpm, stop and go city riding, id go with the "8"'. If on the other hand, you are firing it up and commuting on the freeway for 20 miles, or are a guy who rides 'aggressively' and gets a lot RPM and WOT (wide open throttle), sick with the "9". The hotter plug will keep itself 'clean' or burnt off as there is less porcelain material which is what you want when you're just 'putting' around. The colder plug will help keep you from detonation and/or pre-ignition when you're beating on it. IIRC, most catalogs spec the hotter plug for the Lightnings, and the colder plug for the Firebolt, probably under the presumption that the Firebolts would be run harder. The engines themselves are identical.

 

[WIGGLE2]

^ Sorry...when I started this message, there were no replies. I'm at work and got interrupted so it took a bit 'till I posted it.

 

[user_deleted]

in NGK speak....the lower the plug reference #, the hotter the heat range. i'm on my 8th buell XB and have run NGK DCPR9EIX in every single one of them with great results. this is in ambient temps from 30-105 degrees fahrenheit or 3-35 degrees celsius. ease of starting, smooth idle, nice throttle response, longevity and anti-fouling properties make them the plug of choice.
disclaimer: i am in no way, shape or form associated with NGK of Japan or any of their subsidiaries. recommendations based on personal experiences. your mileage may vary.

 

[RotemXB9]

Thanks!!! Helped me alot!