So now I have some time I will give a bit more info on my first scooby. It has done 81000 miles, fsh, it is getting a major service. The mechanic doing the service was in touch with a friend who worked with the Subaru rally team. He recommended 4 point spark plugs. I've asked him to get them. Has anyone else used these? Just curious.

Thanks

Pretty much everyone here uses NGK plugs here if I'm correct, I personally use pfr6b's for my classic ej20, I think the ej25's use pfr7b's

Are they the best? I dunno. Do they work? Yup. Are they well priced? Yup.

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Pfr6b is standard spec from Subaru 

 

if modded use the 7b 

As matt said most that run extra boost use ngk 7's and make sure they're compatible with your engine size .As the 2.5 heads run a different length plug than the 2ltr heads.

My personal opinion of the "multi point" spark plugs is that they're a bit of a gimmick, although I've got no data to back up my opinion. Basic electrical behaviour is the spark will "jump" across the smallest gap between "prong" and "core" . Therfore only ever "sparking" at 1 point not all 4 at once ?

If it's not broke .....upgrade it 😊

Thanks Guys.

Being a newbie to an Impreza I'm trying to soak up as much info as possible. So running a standard form EJ20 there is not much to be gained with the multi point spark plug?