Harley's since it's threads are plated. Never a black one. Depending on contract of supplier, NKG supplies Harley with their older Softtail plugs. (no cheaper then Harley) Harley's are fairly easy on plugs. Mine will easily go 10K

 

Agreed about Bosch, I didn't recommend it because I did a short Google and there appears no Bosch replacement in this table, maybe it's just outdated/incomplete though.

 

I'd run Champion before I ran Bosch plugs, just because of all the bad experiences with F-150 V8's mostly.

I persoanlly run NGK Iridium everywhere except my very modded F-150 which gets treated to Denso Iridium.

 

I copied this from somebody:

H-D Standard
6R12
H-D Gold
6R12G
H-D Platinum
6R12PP
Screamin' Eagle
EX12S
ACCEL
Y2418P
Autolite
4164
Autolite Platinum
AP4164DP2
Bosch / Platinum
YR6LDE
Champion
RA8HC
Denso Iridium
IXU22
NGK
DCPR7E
NGK Iridium
DCPR7EIX
Splitfire
SF416D

 

nMight sound like nonsense to you, but it's not. I'm not saying in some applications, other plug options wouldn't be better. But, the do have the guys called engineers that work with this stuff. It's when they get handcuffed by government regulations, or damn accountants that the final product gets compromised.

And in the case of a $1 spark plug...I can tell ya...the accountants didn't do it.

But...is this discussion there are 2 guys with a combination of over 160,000 miles on their Sporty that are telling you the Champion plugs are as good as any. If you just insist on not listening to the advise you asked for...... Well, why did ya bother to ask????

 

Put in what the OE suggests. If they call for coppers, putting in double plats will not make more power, increase mpg, or make it run better. They'll just empty your wallet sooner. General rule of thumb regarding plugs;

Champion for Chryslers, HDs, and lawnmowers
Autolite for Ford products
AC Delco for GM products
NGK & Denso for Asian imports and some VWs
Bosch for Euro imports.

 

I've tried the aftermarket thing and have decided to go back to the 6r12 stock plugs. I thought the e3's were the thing to do,,but they fouled so quickly it wasn't worth the money and they didn't do what they promised anyway. They don't cost that much anyway and if you index them you might get better results than before. At least I think I have. Good luck.

 

Dear SportyPig,

who/what are you fighting here?
If it's OP ... he said he doesn't like Champions and would like to hear about alternatives. Looks like a valid question to me. So people discussed some other options here, how is that bad?
If it's me ... that's useless. I'm a technical person and I do not buy all that b/s wannabe pundits on the internet keep telling to each other (until they start believing it's true).

 

Jeff, electricity always takes the path of least resistance, so the spark is only going to jump the E3 electrode that is the easiest path. If you had a coil capable of the equivalent of a lightning bolt it might jump to all three but i don't see a stock coil doing that. I replaced my plugs at 15,000, 50% more than most of you recommended and there was never an issue. I replaced the originals with Accels, there was no change in performance.

 

NGK D7EA are compatible to the Champions + only half a buck more, $2.49 instead of $1.99.