So, What spark plugs are best for a mazda 3 2.0 liter? I remember reading on this board that people recomended either Denzo or NGK, well which is best and which model plug should I choose? I have Bosch Fusion plugs in my motor right now, but it runs shitty with them so I want to get a new set to replace them.

 

NGK Iridium IX or die. Denso's are nice as well just harder to find in a quality iridium.

 

Are iridium plugs the best? or is PLatinum the better performer? I was under the impression that iridiums last longer but aren't as good as platinum, I dind't think that was right, but thats what a friend tried telling me. life length isn't as important to me because I tend to replace my plugs every year or 10,000 miles whichever first, so pretty frequently.

 

Iridium plugs have a much smaller center electrode which makes them able to dissipate heat faster and help prevent pre-ignition. Also, Iridium is much stronger than platinum and lasts longer.

You'd only want to avoid Iriridum in a turbo vehicle that runs very rich as they are easier to foul out.. In that case I'd use copper plugs and replace them every 3k miles.

 

Can you use those plugs in the 2.0L engine? I have browsed the web looking to get some and nowhere shows them as an option. NGK's site shows only the OEM verision and the laser plug and doesn't show them as an option.

 

as of now I can't find the irridium IX 's for the 2.0, but the OEM laser irridiums by NGK are still better than the top of the line bosch plugs or the stock OEM ford plugs. I had the bosch irridium fusion plugs in there and it really did run shitty, the engine was backfiring and idling lower than it was supposed to and there was definitely a loss of torque and power in the lower end. So because I couldn't find any IX's for the 2.0, I just went with the laser irridiums and the car runs much better now, noticeably better.

 

yes, if you get me the OE NGK plug number I'll decode it and get you the IX number. It's a pretty easy read.

 

I think that this is the part number [L303-18-110]. I got it off of Protegegarage.com.... they sell a set of 4 OEM plugs, and if you look at the picture they are NGK Plugs.

 

That's a Mazda part number not NGK.

According to NGK (via their sparkplugs.com site):
ILTR5A-13G

$11.71 a piece from them

http://sparkplugs.com/more_info.asp?...2722&pid=24488

I'm one of those 'turbo and runs really rich' people who use copper plugs so that price seems wild to me :P It's 10x what I usually pay per plug. It should last you 10x as long and perform well though