Time has come to change my plugs on my STi V4, and advice on which are the best replacement plugs?

 

bttt

 

NGK PFR7B
or
DENSO PK22PR8

Not sure what the HKS numbers are..

Rich

 

Rich
I was told NGK PFR6B, do you know the difference between the two - I think it's the heat rating - do you know which it better?

 

Ian,

PFR6B is listed for UK Impreza's.

PFR7B is has a cooler heat rating, and (as I understand it) is better suited to pre MY01 STi's.

I will double check this info. and report back tomorrow.

Rich

 

Be careful with the Denso plugs. A few people (myself included) have had the tip fall/burn off. I know that the HKS plugs are made by Denso, but I think to a higher standard.

Dan

Edited to add, HKS Plug code is S35i

[Edited by Danny Fisher - 4/17/2002 6:12:19 PM]

 

Thanks for that

 

Denso's tip fall off?

Had one of mine IK22 blow at WOT, gear4. MY01 STI RA. Tip was still intact however. *phew*

Drove on 3cyl to my mech who replaced all. As soon as I got my hands on NGK's, I swapped back. Running NGK "Iriway" #8 now. Even colder plug, more suitable to our climate here. No fouling/misfire problems so far.

 

Spoke to the NGK technical department today.

According to their information, PFR6B is the listed plug, but they said that PFR7B would be fine as a performance replacement.
(The guy did have more information, but it was in Japanese and I didn't push him to get it translated.)

If you look at the Power Engineering website, they detail uprated NGK spark plugs next to a picture of PFR7B's.

Hope this helps....


Rich