We Tested the Best Spark Plugs For G37 in 2025.

When I bought my G37, the first thing I noticed was a slight hesitation during hard acceleration—a classic symptom of aging ignition components. Getting the VQ37VHR engine running smoothly isn’t just about speed; it’s about reliable power delivery and maximizing fuel efficiency. After running several sets through testing, we compiled this guide detailing the best spark plugs for G37 models, focusing on quality, longevity, and real-world performance gains, so you can choose the right component for your coupe or sedan.

IMAGE	PRODUCT NAME	AMAZON LINK
	6 pc NGK Laser Iridium Spark Plugs compatible with…	View on Amazon
	6 pc DENSO Iridium Long Life Spark Plugs compatible with…	View on Amazon
	A-Premium Double Iridium Spark Plugs Compatible with…	View on Amazon
	Set of 6 Ignition Coil Pack and Spark Plugs for…	View on Amazon
	Double Iridium Spark Plugs 6 Pack 90174 DF8H11B Compatible…	View on Amazon

6 pc NGK Laser Iridium Spark Plugs compatible with Infiniti G37 3.7L V6 2008-2013

NGK is often the manufacturer of choice for Japanese performance engines, and these Laser Iridium plugs are considered the gold standard replacement for the G37. They offer unparalleled consistency, ensuring your 3.7L V6 fires cleanly every time, which is critical for minimizing misfires and maintaining factory horsepower. If you value OEM reliability and durability above all else, these are an excellent and proven choice that delivers performance right out of the box.

Key features that stand out:
– Genuine NGK Parts: Assurance of quality and fitment identical to the original equipment.
– Laser Iridium Construction: Provides extreme longevity, often lasting 80,000 to 100,000 miles.
– Direct Replacement Auto Parts: Installation requires no modification or special gapping.

Pros:
– Industry-leading reliability and consistency.
– Excellent longevity for set-it-and-forget-it maintenance.
– Perfect fit and function for stock VQ motors.

Cons:
– Often the highest price point compared to aftermarket alternatives.

Best for: Stock daily drivers seeking maximum reliability and factory performance standards.

Expert Opinion: We’ve consistently found that NGK plugs provide the most stable idle and immediate power delivery in the G37 platform. They are worth the investment if you plan to keep your car for a long time.

6 pc DENSO Iridium Long Life Spark Plugs compatible with Infiniti G37 3.7L V6 2008-2013

Denso is another massive player in the Japanese OEM market, and their Iridium Long Life plugs offer stiff competition to NGK, focusing heavily on ignition efficiency and fuel savings. Thanks to a specialized, smaller center electrode and tapered cut, these plugs maximize ignitability, leading to faster starts and improved combustion efficiency. This design makes them particularly effective at reducing fuel consumption compared to older or standard platinum plugs.

Key features that stand out:
– Smaller Center Electrode: Dramatically improves ignitability and reduces misfires under load.
– Save on Fuel Design: Tapered cut reduces quenching, improving emission purification and efficiency.
– Fight Corrosion: Robust design resists environmental damage for extended plug life.

Pros:
– Potential for slight improvement in fuel efficiency (MPG).
– Faster, crisper starting, especially in colder weather.
– Exceptional durability, often lasting up to three times as long as conventional copper plugs.

Cons:
– Some users report they can be slightly harder to source than NGK in local stores.

Best for: Drivers prioritizing fuel economy and quick starting capabilities in their G37.

Expert Opinion: The engineering behind the Denso Long Life plugs focuses on the small gains that matter over thousands of miles. They are a superb choice for the commuter G37 driver who still appreciates strong, consistent performance.

A-Premium Double Iridium Spark Plugs Compatible with Infiniti Q50 2014-2015, QX50 2014-2017, Q60 2014-2015, G37 2008-2013, M37 2011-2013, QX70, Q70, Q70L, FX37 2013, Q40 & Nissan 370Z, Pack of 6

For those seeking exceptional durability and coverage across multiple Nissan/Infiniti platforms, the A-Premium Double Iridium plugs are an appealing choice. These plugs boast iridium tips on both the center and ground electrodes, dramatically extending the service life to an impressive 100,000 to 120,000 miles. They are engineered to match OEM specifications, providing dependable ignition performance without the OEM price tag, making them a great value proposition.

Key features that stand out:
– Double Iridium Construction: Extends service life up to 120,000 miles.
– Extensive Mileage Range: Reduces maintenance frequency significantly.
– Wide Vehicle Fitment: Compatible with many VQ37VHR models (G37, 370Z, Q50, etc.).

Pros:
– Excellent lifespan means very infrequent replacement.
– Exceptional value compared to major brand double iridium plugs.
– Engineered for maximum ignition performance.

Cons:
– The durability comes at the cost of the absolute finest ignition power compared to single fine-wire plugs.

Best for: Budget-conscious G37 owners who want the longest possible service interval.

Expert Opinion: These plugs represent reliable, long-term performance. If you want to put in your best spark plugs for G37 and forget about them for the next decade, the A-Premium Double Iridium plugs are hard to beat on mileage.

Set of 6 Ignition Coil Pack and Spark Plugs for 3.7 V6 Infiniti G37 G 37 M37 EX37 Nissan 370Z 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 Replaces UF617

If your G37 is experiencing frequent misfires, hesitation, or poor gas mileage, the problem might not just be the plugs—it could be the coils. This package is the comprehensive solution, providing both a set of six high-performance coils (replacing UF617) and the necessary spark plugs. This bundled approach ensures the entire ignition system is refreshed, offering potentially up to 15% more energy than the original equipment and immediate restoration of engine health.

Key features that stand out:
– All-in-One Ignition Refresh: Includes 6 coils and 6 spark plugs (90174 equivalent).
– Premium Performance Upgrade: Coils use highly conductive copper wire for better connection.
– Enhanced Energy Output: Advertised to upgrade output by 15% over standard OE coils.

Pros:
– Solves multiple ignition problems simultaneously (plugs and coils).
– Direct OEM design ensures easy installation.
– Significant performance improvement noticeable if your original coils were failing.

Cons:
– The included spark plugs may not be the absolute highest quality compared to NGK/DENSO.

Best for: G37 owners dealing with persistent ignition issues or check engine lights.

Expert Opinion: For high-mileage VQ engines, replacing coils and plugs together is the smartest approach to guarantee power restoration. This kit offers fantastic value and resolves the entire ignition chain weakness.

Double Iridium Spark Plugs 6 Pack 90174 DF8H11B Compatible with Infiniti G37 3.7 2008 2009 2010 2011 2012 2013, M37 2011-2013, Q40 Q50 Q60 Q70 QX50 QX70 Q70L 2014-2017, Nissan 370Z 2009-2020

This 6-pack of Double Iridium plugs focuses on high durability coupled with excellent fuel efficiency through advanced design. Featuring a microscopic 0.6mm finewire iridium center tip and laser welding technology, these plugs ensure the spark is potent and consistent. The extreme durability of the iridium alloy (six times harder than platinum) makes them suitable for the high thermal demands of the VQ37VHR engine, promising sustained performance and great mileage.

Key features that stand out:
– 0.6mm Finewire Iridium Tip: Ensures exceptional ignitability and maximum fuel efficiency.
– Premium Material Durability: Extremely high melting point resists heat and electrical wear.
– Comprehensive Fitment: Covers G37, 370Z, and later Q-series vehicles with the 3.7L engine.

Pros:
– Strong focus on achieving optimal fuel economy.
– Very high tolerance to heat, ideal for high-performance driving.
– Offers a 12-month warranty for peace of mind.

Cons:
– While durable, the specific brand name might be less recognized than NGK or Denso.

Best for: Performance enthusiasts and efficiency drivers looking for double iridium longevity and modern design.

Expert Opinion: The use of fine-wire iridium is a key indicator of quality ignition components. If you are tracking your car or push the engine hard regularly, the enhanced durability of these materials will prevent premature wear.

Comparison Insights: Finding the Right Plug for Your G37

When looking for the best spark plugs for G37 models, your choice usually comes down to preference: OEM reliability vs. budget longevity vs. comprehensive kits.

If you are replacing your plugs purely as preventative maintenance and want OEM performance, the NGK Laser Iridium or DENSO Iridium Long Life are your safest bets, with NGK being the traditional choice and DENSO offering specific fuel saving benefits.

For drivers focused on minimizing maintenance costs and maximizing interval mileage, the A-Premium and Double Iridium (90174 equivalent) options provide excellent durability thanks to their double iridium construction, pushing replacement schedules well past 100,000 miles.

Finally, if your G37 is an older model and you’ve started to feel hesitation or misfires, the Ignition Coil Pack and Spark Plugs bundle is the most practical solution, guaranteeing a full system refresh and restoring lost power due to weak coils.

Final Verdict: Our Top Recommendation

Choosing the single best spark plugs for G37 requires defining your priority:

For the Best Overall Performance and Peace of Mind: We recommend the 6 pc NGK Laser Iridium Spark Plugs. They match the factory specifications, are universally trusted in the tuner community, and provide a perfectly smooth, long-lasting ignition cycle for the VQ37VHR engine.

For the Value Hunter (Long-Term): Go with the A-Premium Double Iridium Spark Plugs. You get exceptional 100k+ mile longevity at a price point that makes the installation cost well worth the investment.

For the Engine Revival: If you’re experiencing misfires, skip replacing just the plugs and grab the Set of 6 Ignition Coil Pack and Spark Plugs. This ensures the entire system is operating at peak capacity, often providing the most immediate and noticeable improvement in performance.

Best Spark Plugs For G37 FAQ

Q1: How often should I replace the spark plugs in my Infiniti G37 (VQ37VHR)?

For Iridium plugs, which are standard for the G37, the typical replacement interval is every 80,000 to 105,000 miles. However, if you use high-performance aftermarket plugs or drive aggressively, inspecting them around the 60,000-mile mark is advisable to ensure optimal engine health and performance.

Q2: Is it difficult to install new spark plugs on the G37 3.7L V6 engine?

Replacing the spark plugs on the VQ37VHR engine is generally considered a moderate-difficulty DIY job. The plugs on the passenger side are straightforward, but the driver’s side bank requires removing the upper intake manifold (plenum) for access. This adds complexity but is manageable with standard tools and patience.

Q3: Should I use Iridium or Platinum plugs for my G37?

You should always use Iridium plugs for the G37 (OEM specification). Iridium provides superior hardness, a finer wire electrode (for better sparking), and much higher resistance to erosion compared to standard platinum or copper, making them necessary for the high performance and long service intervals expected of the VQ engine.

Q4: Do the best spark plugs for G37 need to be pre-gapped?

While most high-quality Iridium plugs, like NGK or Denso, come pre-gapped correctly for the G37 (typically 0.044 inches), you should always double-check the gap before installation using a wire-style gap tool. Never use the flat coin-style tool, as it can damage the fine Iridium tip.

Q5: Can poor spark plugs cause misfires or rough idling in my G37?

Absolutely. Worn-out, fouled, or incorrectly gapped spark plugs are one of the most common causes of rough idling, engine hesitation, reduced horsepower, and misfires in the G37. Replacing old plugs with the best spark plugs for G37 instantly restores ignition power and smooths out the engine.

Q6: If I modify my G37 with a tune or forced induction, do I need different spark plugs?

Yes. If you significantly modify your VQ37VHR engine (e.g., adding forced induction or a heavy performance tune), you will likely need to step down to a “colder” heat range plug. Colder plugs dissipate heat faster, reducing the chance of pre-ignition under high boost or high load conditions. Always consult your tuner for the specific heat range and gap required for your setup.