🔧 NGK BKR6EIX vs BKR7EIX vs BKR8EIX vs BKR9EIX: which spark plugs to choose for your tuned engine?

🔥 SEO Keywords: NGK Iridium spark plugs, BKR6EIX, BKR7EIX, BKR8EIX, BKR9EIX, spark plugs for tuned engine, heat range spark plugs, tuning, engine performance

The NGK BKRxEIX (Iridium IX) spark plugs have become a must-have in the world of automotive performance 🚗. Widely used in turbocharged, naturally aspirated, and modified engines, they offer a stronger spark, longer service life, and excellent heat resistance.

But what’s the difference between a BKR6EIX and a BKR9EIX❓ This article explains everything with precise technical data 🧠 and practical advice 🔍.

📘 1. Understanding NGK BKRxEIX labeling

B: 14 mm thread diameter
K: 19 mm thread reach (3/4")
R: built-in resistor (radio interference suppression)
6 to 9: heat range (the higher the number, the “colder” the plug)
EIX: Iridium electrode (better performance and longevity)

🌡️ 2. Heat range: the key to a proper choice

The heat range defines the plug’s ability to dissipate heat. NGK uses a reverse scale:

BKR6EIX → hot
BKR7EIX → standard/light performance
BKR8EIX → high performance / stage 2-3
BKR9EIX → very cold, ideal for stage 3+, track, racing 🏁

⛔ A plug that’s too hot may cause knocking (pre-ignition), while a too cold plug may foul if it doesn’t reach optimal temperature.

🔬 3. NGK BKRxEIX spark plugs comparison chart

Reference	Heat range	Recommended use	Engine type
BKR6EIX	6	Stock, NA engine	Standard gasoline
BKR7EIX	7	Stage 1-2, light turbo	GTI, TFSI, boosted engines
BKR8EIX	8	Stage 2+, occasional track	Heavily modified engines
BKR9EIX	9	Stage 3+, track intensive use	High-performance builds

⚠️ 4. Installation and maintenance tips

Always check the electrode gap according to the manufacturer’s specs (typically 0.7 - 0.8 mm for turbo builds).
Use a torque wrench when installing (20–25 Nm for aluminum heads).
Replace plugs every 20,000 to 40,000 km depending on usage 🔁.
Always go for a colder plug if you increase boost pressure (e.g. BKR7EIX → BKR8EIX).

🎯 5. Which model fits your setup?

🚙 Stock engine → BKR6EIX
🚀 Stage 1/2 TFSI, GTI, Subaru, etc. → BKR7EIX
🏎️ Stage 2+/3, high turbo pressure → BKR8EIX
🏁 Track days, highly boosted builds → BKR9EIX

🛒 Where to buy your NGK Iridium spark plugs?

At STR Performance, we offer the full NGK Iridium BKRxEIX range ✅ in stock, with fast delivery and expert technical advice 💡.

👉 Browse our spark plug catalog now

💬 Conclusion

Choosing the right spark plug is not a detail. It’s a key factor to optimize ignition, protect your engine, and fully unleash your build’s potential. Don’t neglect this crucial component 🔍. Upgrade to a well-matched Iridium model for your usage and engine setup 🧰.

Comments (0)

No comments at this moment

Only registered and logged customers can add comments

FAQ: The Most Frequently Asked Questions

How do I track my package?

As soon as the shipment is made, you will receive an email with a tracking link. You can also find this link in your customer account, under "My Orders." Delivery is tracked via Chronopost, Colissimo, DPD, or UPS.

How to contact Customer Service?

You can contact our customer service by email at https://strperformance.com/en/ or by phone at +33 01 34 67 70. We are available Monday to Friday, from 9:00 a.m. to 12:00 p.m. and from 2:00 p.m. to 5:00 p.m. Customer service is closed between 12:00 p.m. and 2:00 p.m. Response guaranteed within 24 to 48 hours (excluding weekends and public holidays).

Which countries do you deliver to?

STR Performance ships your orders all over the world: mainland France, French overseas departments and territories, Europe (Belgium, Switzerland, Spain, Germany, etc.) as well as internationally (Canada, Maghreb, overseas, etc.). Our shipping partners include Chronopost, Colissimo, DPD and UPS, depending on the country, weight and size of the package. Shipping costs are automatically calculated at the checkout stage based on your address. Each shipment is tracked online and secure. We deliver to your home, collection point or business depending on the options available in your area.

What are the shipping times?

Shipping times at STR Performance depend on product availability and delivery destination. ✅ Products in stock : dispatch within 24 to 48 working hours after payment validation (excluding weekends and public holidays). 🔄 Products being restocked or personalized : an additional delay may apply (specified on the product sheet or communicated by our customer service). Average delivery times after dispatch : 🇫🇷 Metropolitan France : 1 to 3 working days via Chronopost, Colissimo or DPD 🇪🇺 Europe (Belgium, Luxembourg, Germany, Spain, etc.) : 3 to 7 working days 🌍 DOM-TOM, Canada, Maghreb, and rest of the world : 5 to 12 working days depending on the area Each order benefits from online tracking : you will receive an email with a tracking number as soon as your package is picked up by the carrier. Important : Orders placed after 12 p.m. are generally processed the following business day. Delivery times may be longer during busy periods (sales, promotions, holidays, etc.).

How much are the shipping costs?

Shipping costs are calculated automatically at the checkout stage, based on the weight, volume of your package and your delivery area. We offer several carriers (Chronopost, Colissimo, DPD, UPS) with rates adapted for France, Europe, the French overseas departments and territories and internationally. The exact cost is displayed before payment, once your address has been entered.