[Stubok]

Originally Posted by Dippydo

I thought someone posted them as being the same part number? I gave up on trying to find the stuttering. It came back a little bit now. I will just drive it till it breaks or get a new car. Whichever comes first. Since I have a 100k warranty I don't care anymore. :-(

Definitely a different part number:

N20 Coil 12138616153
F80 Coil 12138616153

N20 Spark plug 12120039664
S55 Spark plug 12120039634

No going to say much about this online, because I'm still in testing and there are critics saying it's placebo, but so far I'm very impressed and happy I changed them to the S55 "High Power" plugs.

[Marshalltj]

Originally Posted by Stubok

Definitely a different part number:

N20 Coil 12138616153
F80 Coil 12138616153

N20 Spark plug 12120039664
S55 Spark plug 12120039634

No going to say much about this online, because I still in testing and there are critics saying it's placebo, but so far I'm very impressed and happy I changed them to the S55 "High Power" plugs.

Did you have to replace the coils also or is that just another recommended change when changing plugs?

[Stubok]

Originally Posted by Marshalltj

Did you have to replace the coils also or is that just another recommended change when changing plugs?

Did not change the coils. my car has only done 10k miles, so didn't feel it necessary. they should last til 50k+ and besides, as I found, the S55 and N20 use the same coil.

Probably not a good idea to install S55 plugs in a stock N20 engine. They may cause other issues since they run a few steps colder than the N20 plugs. Only do it if you are putting into a tuned N20.

[Marshalltj]

Originally Posted by Stubok

Did not change the coils. my car has only done 10k miles, so didn't feel it necessary. they should last til 50k+ and besides, as I found, the S55 and N20 use the same coil.

Probably not a good idea to install S55 plugs in a stock N20 engine. They may cause other issues since they run a few steps colder than the N20 plugs. Only do it if you are putting into a tuned N20.

I am running an AFE Scorcher. I know it only affects boost pressures, so I wonder if it would still be safe to use the S55 plugs?

[Stubok]

Originally Posted by Marshalltj

I am running an AFE Scorcher. I know it only affects boost pressures, so I wonder if it would still be safe to use the S55 plugs?

Are you getting any hesitation or stuttering with the AFE module? If not then I would say leave it alone. If you are, then perhaps give it a go.

The plugs alone are about $100 so not something you want to do on a whim.

[Engelb]

I just had mines changed along with an oil change.. It was about 420 total at BMW...
It wasn't a project I felt comfortable with doing myself..