EJ20G Spark plug difference?

[rxleone]

Going to change the spark plugs in the girlfriends 90' Legacy GT (4EAT, EJ20 turbo). I know you stateside guys didn't get this motor, but I did some checking at the parts store and they say the motor takes NGK BKR6EIX Iridiums, which are about five times more expensive per plug then standard V-Powers.

 

I was going to use just the standard V-Powers. I take it you just drop the IX at the end of the part number to become BKR6E. Are regular NGK plugs okay to use?

 

I figure the iridiums are just a bit of a marketing ploy or last a bit longer to save changing them too often in a DOHC motor, but I'm not fussed about changing them more often. Are the standard plugs just as good to use?

Edited December 17, 2012 by rxleone
typo

[89Ru]

I can't speak for iridiums. Perhaps they are better than platinums. I have not been impressed with platinum plugs in the EJ22 (not OEM) OR double platinums in the EJ25D (OEM). They wear unevenly and after 80km they should be inspected if not sooner. I have seen coppers go 120km and still be evenly worn (EJ22). I think the advice I have been given to stick with copper makes sense, they are cheap and just replace them after 50km. Several recent posts on this subject. Yes all these mileages are in km's not miles. Its been a while since I have seen the southern cross...hope to get back in the southern hemisphere soon.

[Fairtax4me]

BKR6E-11 is the V power copper plug with the same heat range. They'll work just fine, but you may need to re-gap them after 15 or 20 thousand miles.

Spark doesn't jump the plug gap quite as easily with higher cylinder pressure that the turbo creates. This is overcome by closing the gap a bit, but as the plug wears the gap widens and can cause misfire issues under boost.

The iridium tip plugs are more resistant to this problem over the long term, but they cost about 3-4 times as much.

 

If you don't mind pulling the plugs every now and then, standard copper should work just fine.

[rxleone]

Thanks for that. Learn something new every day.

[torxxx]

put V-Powers in it and be done with it. Iridiums are a waste of money. Got tricked into buying them for my SVX a few years ago = random misfires. Put cheap V-powers back in it = misfires gone

[Legacy777]

The reason they call for the iridiums is because the plugs on that motor are a pain in the butt to change, so Subaru calls for plugs that last longer. You can use the standard v-power plugs with the knowledge that you may need to change them more frequently.

[rxleone]

The reason they call for the iridiums is because the plugs on that motor are a pain in the butt to change, so Subaru calls for plugs that last longer. You can use the standard v-power plugs with the knowledge that you may need to change them more frequently.

I've never really had a problem changing plugs on a DOHC motor, maybe because my hands aren't too big. Doesn't bother me changing them every 30,000km or so, that's only about once every two years anyway.