Spark Plugs

[e30 335i]

What is the best spark plug for an 86' e28 m30b34 motor?

irridium?platinum?oem?

thanks in advance.

[Gadea]

from trial and error, I came to think platinum (+2, +4, fusion) are overrated. They ARE no doubt better than the ones you could buy at the dollar store, but they´re in no way superior to some NGK, which is what I´ve been running. Maybe other brands like Denso are good for this motors too, but I can´t really say. Maybe platinum and iridium offer some kind of improvement compared to OEM on other cars.

[619E30]

^ yeah

[Aptyp]

I always install V-Power NGKs

[dnova89]

Yeah just go OEM. You won't see differences except maybe a wierd idle with anything else. I took platinums out for NGK coppers and noticed my car ran a tiny bit better. Whether it's because of the actual metal it's made of, I don't know, that's very controversial, but just go with copper NGKs, that is the most generally accepted consensus among e30 owners, and if not NGKs then at least stay with coppers. Since they're so cheap and it's such an easy job it'd be smart to shorten the intervals in which you change plugs. I plan to do mine every 15k, one of the few simple and inexpensive ways to keep your car running like a champ. :)

Here are the part #'s for the plugs, the OEMs would be Bosch, but most people I've spoken to like NGK's better for one reason or another, I don't think it really makes a difference as long as it's copper.

Bosch: W8LCR
NGK: ZGR5A

Those are for the m20 engine at least, not sure if it also applies to m42's.

[Jaxx_]

For turbo cars I always use coppers, and if not turbo'd from the factory, a bit colder than stock.

On N/As, sometimes the plat/iridium/+2/+3/+4/+zomg 'hype' stuff can deliver better spark if you're running into that issue. For a stock to generally mildly modified motor, I'd still run high quality coppers all day. Unless you're having odd problems with your ignition, just stick to copper. You could try plats/iridium to see if they sort it out.

good luck! :)

[LowR3V'in]

Best spark plug for what exactly?

I use iridium because I don't have to change/regap like coppers.

[e30 335i]

Thanks for all the responses. I think i will go with the NGK copper plugs as i dont mind changing them often.:)

[wildstoats]

Stock engine? Bosch WR9LS or NGK ZGR5A. End of story.