Best Spark Plugs For 5Th Gen 4Runner: NGK and DENSO Options

#1 · Best Overall

1. NGK Laser Iridium

• Core Material: Iridium
• Top Material Type: Iridium
• Compatible with Vehicle Type: Car, Truck
• Thread Size: 14mm

Best for: 2013–2020 4.0L V6 replacement.

Why it ranks #1: Its listing directly fits 4Runner 4.0L V6 models from 2013–2020, includes six genuine NGK plugs, and identifies them as direct replacements.

A six-plug NGK Laser Iridium set explicitly lists the 2013–2020 Toyota 4Runner 4.0L V6, giving owners in that stated range a vehicle-specific replacement starting point. The genuine NGK parts include original packaging and hardware, keeping the listed replacement components together for a plug service.

The 14 mm thread and 0.04-inch gap provide concrete specifications to compare with service requirements, while the iridium core and top identify the electrode material. Its six-plug quantity matches the listing’s 4.0L V6 application, and the stated 2013–2020 range makes the intended 4Runner coverage easy to check. The direct-replacement description supports a replacement workflow; use the product’s confirmed-fit process to verify the specific vehicle before ordering.

Skip it if you own a 2021-or-newer 4Runner; this listing stops at 2020, while NGK 6619 is a general-purpose alternative to investigate.

For owners of a 2013–2020 4Runner 4.0L V6 seeking a six-piece NGK iridium replacement, this listing offers specific application coverage. Treat the stated year range as its boundary and verify your vehicle’s fitment.

Listed on Amazon as: 6 pc NGK Laser Iridium Spark Plugs for Toyota 4Runner 4.0L V6 2013-20

#2 · Best Ruthenium Set

2. NGK Ruthenium HX

Best for: 2013–2020 4Runner ruthenium.

Why it ranks #2: This genuine NGK six-pack is explicitly listed for 4Runner 4.0L V6 models from 2013–2020, with a ruthenium electrode design.

NGK Ruthenium HX plugs are explicitly listed for the 2013–2020 Toyota 4Runner 4.0L V6, making the ruthenium electrode material the key distinction for owners within that range. This six-piece set is described as genuine NGK parts and direct-replacement auto parts, with original packaging and hardware included.

The stated 2013–2020 4Runner 4.0L V6 application gives buyers a clear year-and-engine range to compare with their vehicle, and six plugs provide the listed set quantity. Ruthenium HX identifies the plug type, while the genuine-parts and direct-replacement descriptions frame its role in a replacement service. The listing does not provide thread or gap specifications, so buyers who need those measurements should consult vehicle service information before installation.

Skip it if you need thread and gap measurements stated on the listing; Sixity Auto’s NGK Laser Iridium set specifies both.

For a 2013–2020 4Runner 4.0L V6 owner choosing NGK Ruthenium HX plugs, the explicit application and six-piece quantity are useful boundaries. Check service specifications separately because thread and gap measurements are not provided here.

Listed on Amazon as: 6 pc NGK Ruthenium HX Spark Plugs for Toyota 4Runner 4.0L V6 2013-20

#3 · Best Narrow Fit Range

3. DENSO Iridium Power

• Core Material: Platinum
• Top Material Type: Iridium
• Compatible with Vehicle Type: Car, Truck
• Thread Size: RM

Best for: 2014–2017 tapered-tip iridium.

Why it ranks #3: The six-plug set specifically lists 4Runner 4.0L V6 fitment for 2014–2017 and describes a 0.4 mm iridium tip.

A 0.4 mm iridium tip and tapered-cut U-Groove ground electrode distinguish DENSO Iridium Power plugs listed for 2014–2017 4Runner 4.0L V6 models. This six-piece genuine DENSO set also describes a 360-degree laser-welded assembly, giving owners in that stated range specific construction details to consider for replacement.

The 2014–2017 4Runner 4.0L V6 fitment makes this a targeted option for those model years, rather than the earlier applications listed for several other products. DENSO’s tapered-cut U-Groove ground electrode works alongside the 0.4 mm iridium tip and 360-degree laser-welded assembly as the product’s named design features. The listing connects its larger-spark design with power and fuel economy; its 0.04-inch gap is another detail to compare against service requirements.

Skip it if you need 2018–2020 coverage; Sixity Auto’s NGK Laser Iridium set lists those 4Runner years and the same 4.0L V6.

Choose this for a 2014–2017 4Runner 4.0L V6 when DENSO Iridium Power’s tapered U-Groove and fine iridium tip suit your parts selection. Its stated fitment ends before 2018 models.

Listed on Amazon as: 6 pc DENSO Iridium Power Spark Plugs for Toyota 4Runner 4.0L V6 2014-17

#4

4. DENSO Iridium Long Life

• Core Material: Iridium
• Top Material Type: Iridium
• Compatible with Vehicle Type: Car, Truck

Best for: 2003–2013 DENSO long-life iridium.

Why it ranks #4: This six-pack is listed for 4Runner 4.0L V6 models from 2003–2013 and specifies a 0.4 mm iridium center electrode with a platinum ground strap.

DENSO Iridium Long Life plugs pair a fine-wire 0.4 mm iridium center with a platinum ground strap, distinguishing this six-piece set for listed 2003–2013 4Runner 4.0L V6 models. DENSO also describes the plug as supporting a larger spark, with stated power and fuel-economy benefits.

The supplied 2003–2013 4Runner 4.0L V6 application covers early 5th-gen years through 2013, and the six-plug quantity is stated for that engine listing. DENSO’s 0.4 mm fine-wire center and platinum ground strap define the Long Life construction, while the 0.04-inch gap gives a specification to compare with service information. The description also identifies a patented iridium alloy, stated as 90% iridium, connecting material choice with its long-life positioning.

Skip it if you need a 2014–2017 application; Sixity Auto’s DENSO Iridium Power set names those 4Runner model years.

This suits owners of a listed 2003–2013 4Runner 4.0L V6 who prioritize DENSO’s fine-wire iridium and platinum-ground-strap construction. The stated vehicle range does not extend to later 5th-gen years.

Listed on Amazon as: 6 pc DENSO Iridium Long Life Spark Plugs for Toyota 4Runner 4.0L V6 2003-13

#5 · Best Twin-Tip Design

5. DENSO Iridium TT

• Core Material: Iridium
• Top Material Type: Iridium
• Compatible with Vehicle Type: Car, Truck
• Thread Size: M14x1.25

Best for: DENSO iridium twin-tip service.

Why it ranks #5: Its six genuine DENSO plugs list 2003–2013 4Runner 4.0L V6 fitment and describe 0.4 mm iridium with a 0.7 mm platinum twin tip.

DENSO Iridium TT combines a 0.4 mm iridium tip with twin-tip construction in a six-plug set explicitly listed for 2003–2013 4Runner 4.0L V6 models. DENSO describes a larger spark as translating to more power and fuel economy, giving the product’s design and stated performance rationale a clear connection.

The stated 2003–2013 application gives early 5th-gen owners a specific year range to compare, and the six-plug quantity aligns with the listed 4.0L V6 set. DENSO’s description pairs a 0.4 mm iridium center with a 0.7 mm platinum tip in its twin-tip design, while the M14x1.25 thread and listed gap provide dimensions for service-information comparison. The product’s stated larger-spark benefits are DENSO’s claims, not a vehicle-specific guarantee.

Skip it if you own a 2014–2017 4Runner; Sixity Auto’s DENSO Iridium Power listing covers those model years.

This suits owners of a listed 2003–2013 4Runner 4.0L V6 who want DENSO Iridium TT twin-tip construction. Check the year boundary carefully, as the supplied application does not include 2014 or newer models.

Listed on Amazon as: 6 pc DENSO Iridium TT Spark Plugs for Toyota 4Runner 4.0L V6 2003-13

#6

6. NGK Iridium IX

Best for: Earlier 4Runner fine-wire iridium.

Why it ranks #6: The listing specifies six genuine NGK Iridium IX plugs for 4Runner 4.0L V6 models from 2003–2013, overlapping earlier 5th-gen years.

A fine-wire iridium center electrode and precision laser-welded construction distinguish these NGK Iridium IX plugs for the listed 2003–2013 4Runner 4.0L V6. The product also describes nickel-alloy ground electrodes and identifies fuel-injected and turbocharged engines as intended applications, giving buyers specific construction and use details.

The 2003–2013 4Runner 4.0L V6 range covers early 5th-gen models through the stated final year, while the six-piece quantity suits the listed V6 set. NGK’s fine-wire iridium center electrode and laser-welded construction describe the plug design; nickel-alloy ground electrodes are listed alongside a stated focus on horsepower and torque. The fuel-injected and turbocharged application description is also supplied, but the product’s stated Toyota fitment remains limited to 2003–2013.

Skip it if you need 2014–2017 fitment; Sixity Auto’s DENSO Iridium Power set specifically lists those 4Runner model years.

Consider this for an early 5th-gen 4Runner within the listed 2003–2013 4.0L V6 range, especially when NGK Iridium IX construction matters. The stated Toyota application does not cover later model years.

Listed on Amazon as: 6 pc NGK Iridium IX Spark Plugs for Toyota 4Runner 4.0L V6 2003-13

#7

7. DENSO Platinum TT

• Core Material: Platinum
• Top Material Type: Platinum
• Compatible with Vehicle Type: Car, Truck
• Thread Size: 0.04 in

Best for: 2003–2013 platinum twin-tip.

Why it ranks #7: This six-plug genuine DENSO set is listed for 4Runner 4.0L V6 models from 2003–2013 and uses platinum twin-tip construction.

DENSO Platinum TT plugs use a twin-tip design with a 1.1 mm platinum center electrode, distinguishing this six-piece set for listed 2003–2013 4Runner 4.0L V6 models. DENSO also associates the larger spark with faster starts, more power, and fuel economy, making its stated operating benefits part of the product’s appeal.

The application list covers 2003 through 2013 4Runner 4.0L V6 models, so the year boundary matters when shopping for an early 5th-gen vehicle. DENSO’s twin-tip design pairs a platinum center electrode with a titanium-enhanced ground strap, while the listed 0.040-inch gap gives a measurement to compare with service information. Six plugs match the set’s stated V6 application, and the faster-start claim is tied to DENSO’s Platinum TT description.

Skip it if you have a 2014-or-newer 4Runner; Sixity Auto’s DENSO Iridium Power set lists 2014–2017 4.0L V6 models.

This fits buyers servicing a listed 2003–2013 4Runner 4.0L V6 who want DENSO Platinum TT twin-tip plugs. Its year boundary is important: later 5th-gen models are not included in the stated application.

Listed on Amazon as: 6 pc DENSO Platinum TT Spark Plugs for Toyota 4Runner 4.0L V6 2003-13

#8

8. NGK Iridium LFR6AIX-11

• Core Material: Iridium
• Top Material Type: Iridium
• Compatible with Vehicle Type: Car, Truck
• Thread Size: 14mm (Thread Diameter), 1.25mm (Thread Pitch)

Best for: Wide-heat-range NGK iridium.

Why it ranks #8: It offers six NGK iridium plugs and a stated 14 mm thread diameter, but its listing does not specifically confirm 4Runner fitment.

NGK’s stated wider operating heat range is the defining feature of this six-pack of Iridium Spark Plugs, intended to operate across a broader range than ordinary plugs. The product also names resistance to carbon buildup and pre-ignition, making those operating concerns central to its appeal for buyers evaluating a general NGK replacement set.

The wider heat-range claim connects the iridium plugs to operation across more conditions than ordinary plugs, while the stated resistance to carbon buildup and pre-ignition addresses two specific concerns in the listing. NGK’s patented triple-gasket sealing process is said to eliminate the possibility of combustion-gas leakage. Six plugs are included, and the 14 mm thread diameter with 1.25 mm pitch gives useful dimensions to compare against the vehicle’s requirements.

Skip it if you need explicitly listed 4Runner fitment; Sixity Auto’s NGK Laser Iridium set names 2013–2020 4.0L V6 models.

This suits buyers seeking NGK iridium plugs with a stated wide heat range and triple-gasket sealing process. For a 5th-gen 4Runner, its boundary is the lack of listed vehicle-specific fitment; verify the application before choosing it.

Listed on Amazon as: NGK 6619 Iridium Spark Plugs LFR6AIX-11-6 Pack

#9

9. NGK Iridium LFR5AIX-11

• Core Material: Iridium
• Top Material Type: Iridium
• Compatible with Vehicle Type: Car, Truck
• Thread Size: 14mm

Best for: Eight-plug NGK service quantity.

Why it ranks #9: This NGK iridium set provides eight plugs rather than the six specified by the 4.0L V6 vehicle listings, and fitment requires research.

An eight-plug quantity distinguishes this NGK Iridium IX listing from the six-plug sets in this roundup, enabling buyers who need that quantity to source it in one package. NGK identifies the plug as often specified as original equipment, while the listing also directs buyers to research application before purchase.

The iridium core and 14 mm thread are concrete specifications to compare against a vehicle’s requirements, while the 0.04-inch gap gives another check during parts selection. Eight plugs are included, so the listed quantity should be considered alongside the intended service. NGK’s original-equipment supplier positioning supports brand familiarity, but the product does not identify 4Runner years or engine fitment; the supplied application-research instruction is especially relevant for a 5th-gen purchase.

Skip it if you want an explicitly listed 4Runner application; Sixity Auto’s NGK Laser Iridium set names 2013–2020 4.0L V6 models.

Choose this NGK Iridium IX listing when an eight-plug quantity and its stated iridium specifications suit your parts plan. For a 5th-gen 4Runner, application research remains essential because no model-year fitment is specified.

Listed on Amazon as: NGK (4469) LFR5AIX-11 Iridium IX Spark Plug (8 Pack)

#10

10. A-Premium Iridium Platinum

• Core Material: Platinum
• Top Material Type: Iridium
• Compatible with Vehicle Type: Car
• Thread Size: M14 x 1.25 mm

Best for: Fine-wire platinum-iridium listing.

Why it ranks #10: The listing describes a six-pack and M14 x 1.25 mm thread, but its supplied vehicle-fitment details do not establish 4Runner compatibility.

A fine-wire construction distinguishes this A-Premium six-pack, pairing a platinum core specification with an iridium top material. That combination gives parts shoppers concrete materials to compare, while the M14 x 1.25 mm thread specification helps assess whether the plug’s dimensions match the vehicle application they are considering.

The listing supplies a reference-number crosswalk that includes NGK 6619 and LFR6AIX-11, giving buyers a way to compare this product with named plug references. Its fine-wire description and platinum-core, iridium-top specifications add further points for parts research. However, the supplied vehicle examples do not establish 5th-gen 4Runner fitment, and the stated fitment information is incomplete here; use the listed dimensions and references only as comparison details, not proof of compatibility.

Skip it if you need confirmed 4Runner application coverage; Sixity Auto’s NGK Laser Iridium set explicitly lists 2013–2020 4.0L V6 models.

This is for parts shoppers comparing fine-wire plugs by material, thread size, or listed reference numbers. Its boundary for a 5th-gen 4Runner is that supplied fitment does not confirm the vehicle application.

Listed on Amazon as: A-Premium Iridium Platinum Spark Plugs Pack of 6, Fine Wire, L6 Engine