Platinum spark plugs?

extended change interval - maybe last 3 times longer.

I don't think there's anything else.

?????

The iridium "fine-wire" plugs will fire at a lower voltage - and therefore MAY fire more reliably. They are more resistant to fouling (slightly)

As far as Plats are concerned, if the engine is waste-fire (double ended coil) using single platinums is a waste of money - dual platinums are required to do the job properly.

My beaf with the long life plugs is unless you pull them to check them at about half life, there is a good chance they won't come out, at least in one piece, when required.

So the hype is warranted?

Yousuf Khan

The single platinums were only $1.50 more than the non-platinums, so the cost is no big deal. Why are dual platinums required? What's the difference?

Doesn't anti-seize lubricant prevent them from having trouble coming out?

Yousuf Khan

The platinum tip is designed to keep the electrode from "eroding" due to electron transfer (I think that's what it is called) - with waste spark half the plugs fire backwards - so it is the gtound electrode that "erodes" - dual plats have platinum wafer on both electrodes.

It helps. Too much can cause other problems (like misfire) I've seen plugs installed with antiseize that would not come out 5 years later.

I've been told they're bad news in these engines and to stick with a regular NGK.

-- Todd H.

my wife's Outback (H6) has them from the factory.

???

Second question, is it worth my time to try to change my own spark plugs? Today I tried doing it, and found everything was too cramped. Is this something that's easier done from underneath? A few of the wires were easily accessible, mostly the front cylinders, but the rear cylinders seem to be highly congested. I left them alone for now, awaiting opinions. Mine's an 2.5L H4 too.

Yousuf Khan

You think a SOOB is difficult to change plugs on? Good thing you don't have a 6 cyl mystique, or a PT Cruiser, or a V6 TransSport, or a

A Soob is EASY to get at in comparison any of them.

On my H4, some discussions many years ago convinced me that this was out of money saving to pain in my ass sweet spot, so I have it done professionally.

-- Todd H.

It looks like on one side I'd have to remove the battery, and on the other side I'd have to remove the airbox. I can remove the battery easily, but don't know what to do with the airbox.

A Canadian Tire store quoted me 1.5 hours labour to do this. I wonder if Subie mechanics can do this quicker?

Yousuf Khan

I think you're discovering why it might make sense to shell out $$$ for longer lasting plugs.

;^)

Yeah, because they're so hard to get to- no one wants to change 'em more than every 60K.

Dave

LOL! Next we'll have him buying iridium! ;)

Really, platinum is good for about 75-100,000 miles, and back in the day Toyota specified them for their EFI engines. I'd stay with what's proven.

My dealer did finally replace the spark plugs, they were platinums. He said that that's what's recommended for Subies.

Yousuf Khan

Yup...

You can "upgrade" to iridium, but since you're replacing them you probably have ~100,000 on the car. Sit back and relax for the next

Removing 4 screws gets full access - not worth 1.5 hours of labor at least on 04 outbacks. Took me tops 1 hour and I was in no hurry. I'll do it again in 30k miles with no trepidation. Platinums dont really work better. My 94 Trooper ran better with the Plain NGK's than with the platinums.