Upgrading Coils & Spark Plugs for i30N (What to buy vs. avoid?)

[RyanP]

Hi everyone,

I'm planning to refresh the ignition system on my i30N soon by replacing both the ignition coils and spark plugs. Before pulling the trigger, I wanted to get some community insights on what works best and what I should absolutely avoid.

To give you some context on my current setup:

• Car Model/Year: i30N 2019
• Current Mileage: 45,000km
• Modifications: Upgraded Intake & Downpipe (Still running Stock ECU / No tune)
• Driving Usage: : Daily driven
• Current Spark Plugs: HKS M40XL
• Current Coils: OEM
  
  What I'm looking for:
  

1. Spark Plugs: I’ve heard many people talk about running colder plugs (like HKS or NGK Racing plugs), especially if tuned. What heat range and gap size are you guys running? Any specific part numbers that have been bulletproof?
2. Ignition Coils: Is it worth upgrading to aftermarket high-output coils, or should I just stick with the latest OEM revision?
3. The "Do Not Buy" List: Are there any specific brands or model that caused misfires, rough idles, or premature failure on your N?

Would love to hear your long-term experiences and setups. Thanks in advance for the help!

 

[Bu11eT]

IMO just stick to the same stuff you are already running.
1. Colder Spark Plugs are of no benefit as long as you dont run a tune that requires them.
2. Same goes here. Just stick to OEM. I would not even replace them if you don't have issues with them. The coils are usually rock solid on our cars and not a part that requires regular maintenance.
3. Not that I am aware of.