Spark Plug ? for Turbo

Would the Bosch Platinum +4 spark plugs be any better or any worse to use in a turboed Civic than the Iridium plugs?

I'm not an expect on the subject, but I don't think there is much to gain between Bosh Platinum plugs and the +2 and +4's they offer. I think the regular platinums are just as good. The Iridiums, I think, are better because they can operate at higher temperatures for longer. Though I don't think spark plugs make that much of a differnece anyways. Any good plug will work fine, unless you have some super modded car. But don't take my word for it.

I will say one thing right now. The Bosch platinum plugs are horrible. They tend to work great for about three months then they begin to misfire and burn up. They are horrible plugs. If I were you I would get a set of Denso or NGK Iridium plugs. I saw a huge difference between the NGK Iridium IX and the Bosch Platinums in my 89 GTC.

Also, if you ever plan to use nitrous don’t use ANY platinum plugs. Platinum is a catalyst for nitrous.

thanks guys. Im glad you told me about platinum being a catalyist. I'm planning on adding a 50hp shot to my civic. I am currently running the platinum +4s in my car now with 7psi of boost and have not had any problems. I have always heard to use iridium plugs for nitrous but I never knew why. thanks

If I were you I would get a set of Denso or NGK Iridium plugs.

Yep thats what i would use. Prefferably i would use Denso but thats just a personall prefferance, because i saw the Denso Supra in real life and it looked real nice :), but im sure they both perform equally.

yes i vouch for the denso's iridium in my car...they are a million times better than those crap motorcraft i used to have.....


and yes bosch platinum are trash

Dude man dont waste your money on a set of $30 or $40 spark plugs with a turbo your just going to fry them any way regular NGK's work just fine.

If I were you I would use the NGK Cold Plug, they are usually a special order item but they work great, they cost about 2 bucks a piece.

Originally posted by funkdaflex1
Dude man dont waste your money on a set of $30 or $40 spark plugs with a turbo your just going to fry them any way regular NGK's work just fine.

I agree. Ask Honda or your COMPETENT local auto parts store for plugs either one or two heat ranges colder than stock. Also use NGK plugs for Gods sake, I would suggest just one range colder for under 10psi.

Whoa, never realized Bosch platinums were no good. Guess I gotta swap them out for some NGK's. Glad I only spent $1 apiece on the platinums and not $6 apiece for the +4's. O well, live and learn.

Go with the Denso Iridium plugs. You'll never regret it. Also, go one number colder for the turbo and close the gap a little.

Originally posted by Gulftech
Go with the Denso Iridium plugs. You'll never regret it. Also, go one number colder for the turbo and close the gap a little.

I had denso iridium plugs and I regret it. A waste of $50 if you ask me. But hey they claim 10 hp addition so they must really work right. :rolleyes:

Originally posted by maxspeedhonda


I had denso iridium plugs and I regret it. A waste of $50 if you ask me. But hey they claim 10 hp addition so they must really work right. :rolleyes:

What didn't you like about them?

Originally posted by Polygon


What didn't you like about them?

For one, I noticed no improvment whatsoever, even on a more modded motor than most people have around this board. For the price, they are just ridiculous. I use one heat range colder ngk's now and it still runs the same. Plus like mentioned before, turbo motors tend to go through plugs more rapidily than NA motors, so why the heck would I want to waste $40-$50 when I can get four for under $10?

I agree, I have a fully built gsr, running 18 pounds daily, every import shop I have gone to told me to use nothing but NGK Cold plugs, gapped between, .30 and .32