Which ones were there from the factory?

Dealer's parts department says I need regular,

but the same dealer did put platinum in it couple of years ago, when they did the tune-up.

 

Does it make a difference between the regular and platinum, except price?

 

-Michael

The stock plugs were regular. I've replaced mine with regular NGKs the first time around and then because it's such a pain to replace them, I switched to NGK Iridium IX for longer change intervals so I wouldn't have to replace them so often. I would stick with NGK or Denso brand plugs in whatever flavor you choose keeping in mind that regular copper plugs need to be changed more often (30K miles) than the Iridium or Platinum (60K miles maybe more). I have personally had a bad experience with Bosch platinum +4s in my wife's 93 legacy. Some guys have run Bosch with no problems, but for some weird reason, the Bosch platinum +4s act funny in a lot of Subaru engines. My wife's got standard Denso plugs in hers right now and they run great as well.

I've been using Bosch 4-Way Platinum for the last 120k miles. It definitely improved my motor a bit. My cruising rpms went down by about 50rpms at the same cruising speeds.

 

 

Which ones were there from the factory?

Dealer's parts department says I need regular,

but the same dealer did put platinum in it couple of years ago, when they did the tune-up.

 

Does it make a difference between the regular and platinum, except price?

 

-Michael

Which ones were there from the factory?

Dealer's parts department says I need regular,

but the same dealer did put platinum in it couple of years ago, when they did the tune-up.

 

Does it make a difference between the regular and platinum, except price?

 

-Michael

 

Bosch = PO301/303, PO302/304:horse:

I've been using Bosch 4-Way Platinum for the last 120k miles. It definitely improved my motor a bit. My cruising rpms went down by about 50rpms at the same cruising speeds.

 

 

I don't understand, about your rpm difference, had you a slipping clutch?

I don't understand, about your rpm difference, had you a slipping clutch?

 

No, it's an auto tranny. My guess, it was producing a bit more power at same rpm as before. Hence the need to reduce rpm to maintain the usual cruise speeds. Granted, it was only 50 rpms, but every little bit helps

I haven't changed my plugs.... ever... and i've had the car since 107k.. it's at 176k.... think it's about time?

I haven't changed my plugs.... ever... and i've had the car since 107k.. it's at 176k.... think it's about time?

 

Hopefully, the guy who owned the car before you used anti-seize on the spark plug threads before he installed them. If he didn't, believe me, you'll know.

I've been using Bosch 4-Way Platinum for the last 120k miles. It definitely improved my motor a bit. My cruising rpms went down by about 50rpms at the same cruising speeds.

 

It's bad enough you're using Bosch Plats in a Subaru, but I hope you didn't just say you've been using the SAME Bosch Plats for 120k miles!!

 

02 Legacies take NGK Platinums factory. You need to use those plugs when you replace them. The ignition system is designed to use a platinum plug, and using a copper plug might affect performance.

When I was at the dealership the other day picking up some OE/NGK wires for the wagon the parts counter guy offered me a deal on OE/NGK platinum plugs. I scoffed and said that coppers generally make a slightly hotter spark AND you have to change them out often enough that they don't get stuck in the heads and ruin your weekend. The parts counter guy looked at me kinda funny but the dealer's mechanic standing behind him laughed heartily and agreed with me.

 

So in my mind I feel better off sticking with copper plugs.

I switched to NGK Iridium IX for longer change intervals so I wouldn't have to replace them so often.

 

I'll second this statement, but add for higher performance also.

 

While I like Bosch Platimum and had used them for years, Iridium is the best plug out there right now. They are durable and the Iridium acts as a catalyst, just like platimum, but better, to allow for a hotter spark at the same gap and voltage as platinum.

 

Jack

not to hijack the thread, but dont forget about the wires!!! i used to work at an auto parts store, and we had a display set up to a couple of coils and 2 sparkplugs, one "fat" wire and one o.e. and the fat wire DEFINATELY made more spark... just my .02$

I haven't changed the plugs in a Sube but in my 1988 VW Golf, now with over 245000 miles, I ran my first set of Bosch platinums for well over 100000 miles. I just removed them every 25 to 30 thousand miles, and since they looked good I lightly brushed them, regapped them, put fresh anti-seize on the threads, and put them back in. I finally replaced them a couple years ago when I figured I'd taken the spark plug frugality thing far enough. But I never had a problem with them.