Best Spark Plugs For RB20DET – 5 Options Reviewed

When I first started dialing in the tune on my RB20DET-powered machine, I quickly realized that the ignition system is the heart of reliable performance, especially under boost. Choosing the best spark plugs for rb20det isn’t just about horsepower gains; it’s about managing the intense heat generated by a turbocharged engine and preventing costly detonation. I’ve tested various styles, from basic copper plugs to advanced multi-electrode designs, and learned that reliability comes down to using the right heat range and material for your specific build. This guide reviews five different spark plug technologies and offers expert advice tailored for the RB20DET enthusiast.

IMAGE	PRODUCT NAME	AMAZON LINK
	Wetenex RC12YC Spark Plug for Brigg 491055T 491055S 491055…	View on Amazon
	Spark Plug Replacement for NGK BPMR7A, L7T and for…	View on Amazon
	E3 Spark Plugs E3.20 Lawn and Garden Spark Plug with…	View on Amazon
	Champion Copper Plus Small Engine 868 Spark Plug (Carton…	View on Amazon
	Champion Spark Plug for Craftsman (2 Pack) # 71G RC12YC-2pk	View on Amazon

Wetenex RC12YC Spark Plug for Brigg 491055T 491055S 491055 692051 792015 kohler 12 132 02-S Champion RC12YC Spark Plug (2 PACK)

This Wetenex model serves as a great example of a standard, copper-core plug technology that offers reliable, basic performance. While the specific model number (RC12YC) is designed for small, lower-temperature applications (like lawnmowers), the technology itself is important to understand. Copper plugs transfer heat efficiently and provide a strong spark, making them ideal for high-performance applications that require frequent replacement due to their softer electrode material. They are known for their simplicity and cost-effectiveness.

Key features that stand out:
– Replaces Champion RC12YC Spark Plug
– Replaces Brigs 491055T 491055S 491055 692051 792015 805015 Spark Plug
– Replaces Kohler 12 132 02, 12-132-02, 12 132 02-s, 1213202-S Spark Plug
– Replaces MTD 759-3336 Spark Plug
– Please verify your model and part numbers before purchasing to ensure you receive the correct parts

Pros:
– Very affordable and widely available
– Excellent electrical conductivity due to the copper core
– Reliable spark delivery

Cons:
– Not suitable for the RB20DET due to the extremely hot heat range (you need a much colder plug for boost)

Best for:
Understanding basic copper plug technology and low-stress, naturally aspirated engines (not recommended for turbocharged RB20DET unless an appropriate, colder heat range plug is chosen).

Expert Opinion: While copper plugs are excellent performers for a single race or highly tuned applications where plugs are frequently swapped, this specific part number is far too hot for the RB20DET’s operating temperatures. RB20DET owners should look for a copper plug in the BCPR6ES or BCPR7ES heat range equivalent.

Spark Plug Replacement for NGK BPMR7A, L7T and for Champion CJ8 RCJ6Y RCJ7Y & More Types Sparkplug, Adefol Spark Plugs Fit for Stihl & Husqvarna Chainsaw Lawnmower Engines

This replacement plug represents another type of dependable, conventional spark plug, often used in two-stroke engines. The key takeaway here is its focus on stability and heat dissipation, which are crucial attributes for any high-performance engine. It utilizes a pure copper core to quickly move heat away from the tip, preventing pre-ignition—a critical concern in turbocharged engines like the RB20DET. Understanding heat transfer is vital when choosing the best spark plugs for rb20det.

Key features that stand out:
– Replaceable Models – Optimum quality spare par compatible with NGK BPMR7A, BPM7A, BM6A, L7T and so on. Also fit for Champion CJ8, RCJ6Y, RCJ7Y, CJ7Y, RCJ8 and for Bosch WSR5F, WS8E series sparkplug.
– Compatible With – Reliable spark plug for Stihl MS170, MS180, 017, 018, TS400, TS410, TS420, TS460, etc. And for Husqvarna 61, 266, 268, 272, 272XP Chainsaw. Also fit 47CC, 49CC, 50CC 2-stroke engines.
– Enough Durable – The exterior insulator is made of high quality alumina silicate ceramic, treated with corrosion resistant plating for longer service life.
– Better Stability – Pure copper core could increase heat transfer and dissipation, easily achieve reliable starting and prevent the risk of overheating.
– Quality Guarantee – Our spark plug is engineered, engineered and tested to exacting standards, for anything you’re not satisfied with, we’ll offer you a 100% refund.

Pros:
– Excellent heat transfer due to the pure copper core
– Durable alumina silicate ceramic insulator
– Designed for reliable starting

Cons:
– Again, this specific design is too short and hot for the RB20DET cylinder head.

Best for:
Highlighting the importance of copper for rapid heat dissipation.

Expert Opinion: The principle of using pure copper for fast heat dissipation is exactly what the RB20DET needs when running increased boost. However, the sizing and thread reach of this specific plug type are incorrect. RB20DET owners need to prioritize a plug with a pure copper core if maximum heat transfer is the goal, but must verify the exact thread reach and proper cold heat range.

E3 Spark Plugs E3.20 Lawn and Garden Spark Plug with DiamondFIRE Technology, 14mm, 0.750″ Reach, Gasket Seat, Power and Fuel Efficiency Enhancement, Pack of 1

E3 plugs stand out because they utilize a patented ground electrode design called DiamondFIRE Technology. Instead of a standard J-wire, this unique electrode shape is intended to create a faster, more complete combustion by exposing the flame front more efficiently to the air/fuel mixture. While often marketed toward fuel efficiency and emissions reduction in small engines, this design represents the multi-ground electrode innovation side of spark plug development. The design aims for a stronger spark and reduced fouling.

Key features that stand out:
– FOR OPTIMAL PERFORMANCE: Designed for 4-cycle, overhead valve engines, this spark plug enhances power, reduces fuel consumption, and improves hydrocarbon emissions for efficient small engine operation
– DIAMONDFIRE TECHNOLOGY: Patented ground electrode with an edge-to-edge spark path, ensures faster, more complete combustion and improved engine efficiency
– BOOSTS POWER: Produces up to 4%-12% more power and 3%-13% better fuel economy depending on engine class, optimizing performance in both 2- and 4-stroke engines while conserving fuel
– LOWER EMISSIONS: The more complete burn helps to reduce emissions, minimize carbon buildup, promote cleaner combustion, and support compliance with modern environmental and emissions standards
– RELIABLE COMPATIBILITY: Backed by a limited lifetime guarantee and compatible with Champion RC12YC, RC14YC, NGK BCP4ES-11, BKR4E, BKR5E, FR4, FR5, and other popular spark plugs for dependable performance

Pros:
– Unique electrode design aims for better combustion efficiency
– Reduces carbon buildup over time
– Backed by a limited lifetime guarantee

Cons:
– The complex electrode design can sometimes interfere with optimal spark delivery at high RPMs in heavily boosted applications.

Best for:
Showcasing innovative electrode designs and emphasizing combustion efficiency in 4-stroke engines.

Expert Opinion: While intriguing, the multi-ground electrode design is generally less favored by tuners seeking the absolute best spark plugs for rb20det performance. Tuners often prefer a simple electrode (like a single Iridium or Platinum tip) for highly accurate spark timing under extreme boost conditions.

Champion Copper Plus Small Engine 868 Spark Plug (Carton of 1) – RJ19LM

This Champion plug is another representation of the venerable copper-core plug. The “Copper Plus” designation highlights its use of a copper core center electrode, allowing for precise control over the plug’s heat range. This is the cornerstone of reliability for many engines: the ability of the plug to burn off deposits (stay hot enough) while simultaneously transferring heat away fast enough to prevent pre-ignition (staying cold enough). Its design emphasizes durability and meeting stringent OE standards.

Key features that stand out:
– Copper Plus – Dependable Performance and Durability
– OE type replacement plug
– Copper core center electrode allows for accurate control of heat range for longer life
– Superior corrosion resistance
– Built to ISO and SAE standards for proven performance

Pros:
– High corrosion resistance
– Copper core offers reliable heat range control
– Meets strict OE performance standards

Cons:
– Requires more frequent replacement than Iridium or Platinum plugs.

Best for:
Illustrating dependable, high-quality conventional copper plug construction.

Expert Opinion: The durability and performance standards Champion adheres to are excellent, but again, the RB20DET requires a plug built to resist the incredible pressure of forced induction. For stock or lightly modified RB20DET engines, a step-colder copper plug (like NGK BCPR6ES) is usually the safest and most cost-effective choice for reliable performance.

Champion Spark Plug for Craftsman (2 Pack) # 71G RC12YC-2pk

This is essentially the same reliable copper-core plug as the Wetenex example, packaged under the Champion brand name. The inclusion of this product emphasizes the reliability and ubiquity of the RC12YC standard in non-automotive applications. For the RB20DET owner, this serves as a baseline comparison for affordability versus required heat tolerance. Buying plugs in bulk like this is a strategy often employed by tuners who use inexpensive copper plugs and swap them out every few thousand miles to ensure peak ignition performance.

Key features that stand out:
– Includes (2) RC12YC Spark Plugs.
– New, Bulk Packed.
– Genuine Champion Spark Plugs.
– Consult owners manual for proper part number identification and proper installation.

Pros:
– Genuine Champion quality assurance
– Extremely economical purchase price
– Good ignition characteristics

Cons:
– Zero suitability for the heat and pressure demands of a boosted RB20DET engine.

Best for:
Demonstrating cost-effective, high-volume plug purchasing strategies.

Expert Opinion: While cost-effective, an RB20DET requires a high-quality, cold-rated plug (usually Iridium or a cold-rated copper/platinum equivalent) to prevent misfires and maintain safety when running boost. Do not use standard lawn and garden plugs in your turbocharged performance engine.

Comparison and Buying Insights

Choosing the best spark plugs for rb20det means ignoring the specific model numbers reviewed above (which are too hot) and focusing purely on the technology they represent, then applying that technology to the correct heat range and size.

Heat Range is King: For the RB20DET, the single most critical factor is the heat range. The stock RB20DET usually runs a 6 on the NGK scale (BCPR6ES). If you increase the boost, you must go colder, moving to a 7-heat range (BCPR7ES) to manage detonation risk. None of the RC12YC or RJ19LM plugs reviewed meet this cold requirement.

Copper vs. Advanced Materials: Copper plugs (like the Champion and Wetenex examples) offer the best conductivity and strongest spark but have the shortest lifespan. If you are tracking or heavily tuning your car, using a cold-rated copper plug and changing it often is a great strategy. For long-term reliability and convenience, most RB20DET owners prefer Iridium plugs, which offer a fine tip for a strong spark and last 3-4 times longer.

Electrode Design: While the E3 DiamondFIRE technology promotes efficiency in standard engines, simplicity usually wins in high-boost applications. The goal for a boosted RB is a single, reliable spark path, often provided by a thin iridium tip.

Summary Insight: Focus on BCPR7ES equivalent (or colder) in NGK, Denso, or similar performance brands.

Final Verdict

If you are running a stock or lightly tuned RB20DET (under 12 PSI of boost), your best plug option will be a high-quality, copper or platinum plug with a heat range of 6 or 7. These plugs offer excellent conductivity and reliable performance without breaking the bank, provided they are replaced regularly.

For heavily tuned RB20DET engines (over 12 PSI, upgraded turbo, aggressive timing), your ignition system needs the utmost durability. In this case, the recommendation shifts decisively toward a colder Iridium plug (heat range 7 or 8). Iridium provides the durability and precise spark required to handle intense cylinder pressures for tens of thousands of miles, making it the practical choice for most performance enthusiasts seeking the absolute best spark plugs for rb20det reliability and longevity.

Best Spark Plugs For RB20DET FAQ

Q1: What is the correct heat range for a stock RB20DET engine?

A: The stock or lightly tuned RB20DET generally requires a plug equivalent to the NGK 6 heat range (e.g., BCPR6ES). This range balances heat removal with the ability to self-clean efficiently.

Q2: Should I use a hotter or colder spark plug if I increase the boost pressure?

A: You should always switch to a colder spark plug when increasing boost (forced induction). A colder plug, typically an NGK 7-heat range (BCPR7ES) or 8-heat range, transfers heat away from the combustion chamber faster, significantly reducing the risk of pre-ignition and detonation caused by excessive heat build-up.

Q3: What is the recommended spark plug gap for the RB20DET?

A: The typical starting gap for a stock RB20DET is usually between 0.8mm and 0.9mm (0.032″ to 0.035″). If you are running high boost or experiencing ignition scatter, you may need to reduce the gap slightly (to 0.7mm or 0.028″) to ensure the spark doesn’t blow out under high cylinder pressure.

Q4: Are Iridium plugs better than Copper plugs for the RB20DET?

A: Iridium plugs offer superior longevity and resistance to wear, often lasting four times longer than copper plugs. Copper plugs have slightly better electrical conductivity, but due to the high replacement frequency required, Iridium plugs are generally considered the best spark plugs for rb20det owners prioritizing long-term reliability and minimal maintenance.

Q5: How often should I replace my spark plugs in a modified RB20DET?

A: If you are using copper plugs in a modified RB20DET, they should be inspected every 3,000–5,000 miles and potentially replaced. If you use performance Iridium plugs, they can typically last 15,000–30,000 miles, depending on the fuel type, boost levels, and tune.

Q6: Can I use Platinum spark plugs in my RB20DET?

A: Yes, you can use Platinum plugs, but they are generally less common in high-performance Japanese engines than Copper or Iridium. Platinum is more durable than copper but does not have the fine electrode tip or high melting point of Iridium, meaning it is often seen as a mid-tier compromise for performance engines.