Best Spark Plugs For 5Th Gen 4Runner: 9 Options Compared

#1 · Best Overall

1. NGK Laser Iridium

• Core Material: Iridium
• Weight: 11.52 oz
• Gap Size: 0.04 in

Best for: 2013–2020 NGK replacement set.

Why it ranks #1: The listing explicitly fits the 4.0L V6 4Runner from 2013–20 and includes six genuine NGK plugs with original packaging and hardware.

The stated 2013–2020 Toyota 4Runner 4.0L V6 compatibility is this six-pack’s clearest advantage, giving owners in that range a direct-replacement NGK Laser Iridium option. Genuine NGK parts, original packaging, and included hardware make it a specifically identified replacement set rather than a general-purpose plug listing.

The six-plug quantity suits a 4.0L V6 replacement set, while the stated 2013–2020 4Runner application narrows the intended vehicle range. Iridium is listed as both the core and top material, identifying the electrode material without making unsupported performance claims. The listing also calls these direct replacement auto parts and says original packaging and hardware are included. Its 14 mm thread size and 0.04-inch gap provide additional specifications for buyers checking the listed plug details.

Skip it if you own a 2021-or-newer 4Runner; this listing names compatibility only through 2020.

This set suits owners of a 2013–2020 Toyota 4Runner 4.0L V6 seeking NGK Laser Iridium plugs with stated direct-replacement status. Its listed application ends in 2020, so check the year range before choosing it.

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

#2 · Ruthenium Option

2. NGK Ruthenium HX

• Weight: 11.5 oz

Best for: 2013–2020 NGK Ruthenium HX.

Why it ranks #2: This six-plug NGK set explicitly lists 4.0L V6 4Runner fitment from 2013–20, matching the broadest stated range among these options.

NGK Ruthenium HX is the defining material and series named for this six-plug set, which is explicitly listed for 2013–2020 Toyota 4Runner 4.0L V6 models. The listing also identifies genuine NGK parts, original packaging, included hardware, and direct-replacement status.

The stated 2013–2020 4Runner 4.0L V6 application gives buyers a broad, clearly named model-year range within the fifth generation. NGK Ruthenium HX identifies the plug series, while the listing calls these genuine NGK parts and describes them as direct replacement auto parts. Original packaging and hardware are included. Unlike the other NGK listing here, the supplied information gives no thread or gap specifications, so this description provides less dimensional detail for comparing plugs.

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

This set suits 2013–2020 4Runner 4.0L V6 owners seeking NGK Ruthenium HX plugs with stated direct-replacement status. Buyers who need listed thread and gap measurements for comparison should note those details are not supplied here.

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

#3 · Long-Life Electrode

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3. DENSO Iridium Long Life

• Weight: 11.5 oz

Best for: 2014–2017 DENSO long-life set.

Why it ranks #3: Its six-plug set explicitly fits 2014–17 4.0L V6 4Runners and lists a 0.4mm iridium center electrode with a 0.7mm platinum ground electrode.

The stated 2014–2017 Toyota 4Runner 4.0L V6 application places this DENSO Iridium Long Life six-pack in a later fitment range than the 2003–2013 version. Its described 0.4 mm iridium center electrode and 0.7 mm platinum ground electrode specify the plug’s construction.

This listing names 2014, 2015, 2016, and 2017 4Runner 4.0L V6 models, giving owners in those years a clearly stated vehicle range. DENSO Iridium Long Life plugs use a fine-wire 0.4 mm iridium center electrode and a 0.7 mm platinum ground electrode, according to the supplied description. Those construction details help distinguish this set when comparing electrode designs. The listing calls DENSO an OE manufacturer and describes a larger-spark benefit, without providing a measured performance figure.

Skip it if you own a 2018-or-newer 4Runner; the NGK Laser Iridium set lists compatibility through 2020.

This set suits 2014–2017 4Runner 4.0L V6 owners looking for DENSO Iridium Long Life plugs with specified electrode materials. Its stated application does not include 2018 or newer model years.

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

#4 · Fine-Tip Design

4. DENSO Iridium Power

• Core Material: Platinum
• Weight: 11.52 oz
• Gap Size: 0.04 in

Best for: 2014–2017 DENSO Iridium Power.

Why it ranks #4: The listing covers 2014–17 4.0L V6 4Runners and specifies a 0.4mm iridium tip, tapered cut, and U-Groove ground electrode.

A tapered-cut U-Groove ground electrode distinguishes these DENSO Iridium Power plugs, alongside a 0.4 mm iridium tip and 360-degree laser-welded assembly. The six-pack is listed for 2014–2017 Toyota 4Runner 4.0L V6 models, giving buyers both a defined electrode design and year range.

The stated 2014–2017 4Runner 4.0L V6 application helps buyers narrow the set to named model years. DENSO’s listing specifies a tapered-cut U-Groove ground electrode, a 0.4 mm iridium tip, and 360-degree laser welding; these details identify its construction rather than promising an unlisted result. The product is labeled Iridium Power, and the description claims a larger spark. Its supplied fitment range is limited to the four listed years.

Skip it if you have a 2018–2020 4Runner; Sixity Auto’s NGK Laser Iridium set lists those years.

This option suits owners of a 2014–2017 4Runner 4.0L V6 who want the listed DENSO Iridium Power electrode design. Its year coverage is narrower than the 2013–2020 NGK Laser Iridium set.

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

#5

5. DENSO Platinum TT

• Core Material: Platinum
• Weight: 11.52 oz
• Gap Size: 0.04 in

Best for: 2014–2017 DENSO platinum twin-tip.

Why it ranks #5: This six-plug set lists 2014–17 4.0L V6 4Runner fitment and uses a platinum center electrode with a titanium-enhanced alloy ground electrode.

A 1.1 mm platinum center electrode paired with a titanium-enhanced alloy ground electrode defines this DENSO Platinum TT six-pack. Its stated application is 2014–2017 Toyota 4Runner 4.0L V6, giving owners in those model years a specifically identified platinum twin-tip option.

The listing names 2014–2017 Toyota 4Runner 4.0L V6 models, so the application is specific but limited to those years. DENSO Platinum TT plugs use a 1.1 mm platinum center electrode and a titanium-enhanced alloy ground electrode, according to the supplied details. The description also claims faster starts and improved performance, though it supplies no measured figures. A 0.04-inch gap is listed in the specifications, adding a concrete comparison point for buyers.

Skip it if you own a 2018–2020 4Runner; Sixity Auto’s NGK Ruthenium HX set lists that later fitment.

This DENSO Platinum TT set suits 2014–2017 4Runner 4.0L V6 owners who prefer its specified platinum center and titanium-enhanced ground electrode. Its stated fitment ends in 2017, so newer years are outside the listed range.

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

#6

6. DENSO Iridium Long Life

• Core Material: Iridium
• Weight: 11.52 oz
• Gap Size: 0.04 in

Best for: Earlier 4Runner DENSO long-life set.

Why it ranks #6: The six-plug DENSO set explicitly fits 2003–13 4.0L V6 4Runners, so its stated range only overlaps the early years of the 5th generation.

DENSO Iridium Long Life plugs are explicitly listed for 2003–2013 Toyota 4Runner 4.0L V6 models, making the 2013 cutoff the key fitment detail for this six-pack. The listing also identifies a fine-wire 0.4 mm iridium center electrode and a platinum ground strap.

The named application covers 2003–2013 4Runner 4.0L V6 models, so its stated range reaches only the earliest years of the fifth generation. DENSO’s fine-wire 0.4 mm iridium center electrode and platinum ground strap distinguish the listed electrode construction. The description also calls the plug Iridium Long Life and identifies a 0.044-inch gap in its vehicle-specific details. These specifics help buyers compare the construction and application, but do not extend fitment beyond the listed years.

Skip it if you own a 2014-or-newer 4Runner; the DENSO Long Life set listed for 2014–2017 names a later range.

This set suits owners of a 2003–2013 4Runner 4.0L V6 who want DENSO Iridium Long Life construction. Its application includes only the 2010–2013 portion of the fifth generation, so later years fall outside its stated range.

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

#7 · Eight-Plug Pack

7. NGK Iridium IX

• Core Material: Iridium
• Weight: 11.52 oz
• Gap Size: 0.04 millimeters

Best for: Earlier DENSO twin-tip option.

Why it ranks #7: NGK lists iridium construction and an 8-pack, but the listing does not specify 4Runner compatibility and supplies more plugs than this V6 application needs.

DENSO Iridium TT combines a 0.4 mm iridium center with a 0.7 mm platinum ground electrode, giving this six-plug set a specifically described twin-tip construction. Its stated Toyota 4Runner 4.0L V6 application covers 2003–2013, with a 0.040-inch gap listed in the description.

The 2003–2013 4Runner 4.0L V6 application makes this an earlier-year option, including only the first portion of the fifth generation. DENSO’s Iridium TT description specifies a 0.4 mm iridium center and 0.7 mm platinum ground electrode, linking the model name to concrete electrode materials and dimensions. The listing describes larger-spark benefits, but provides no measured outcome. Its stated 0.040-inch gap gives buyers another detail to compare during parts selection.

Skip it if you need a plug set listed for 2014–2017; Sixity Auto’s DENSO Iridium TT listing ends at 2013.

This DENSO Iridium TT set suits owners of a 2003–2013 4Runner 4.0L V6 interested in its stated twin-tip electrode construction. For fifth-generation shoppers, its fitment applies only through 2013, not later model years.

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

#8

8. NGK LFR5AIX-11

• Core Material: Iridium
• Weight: 0.27 g
• Gap Size: 0.04 in

Best for: Eight-plug NGK Iridium IX set.

Why it ranks #8: This NGK iridium plug listing provides an 8-pack and 14mm thread size, but gives no specific 4Runner year or engine fitment.

An eight-plug quantity distinguishes this NGK Iridium IX listing from the six-plug sets in this roundup, making its package quantity the key consideration for shoppers planning a replacement. NGK also describes its plugs as often specified as original equipment and emphasizes OEM-manufacturer quality and reliability.

The listing identifies an eight-pack of NGK Iridium IX plugs, so quantity is an important purchase-planning detail; it does not state that all eight are needed for a 4Runner. Iridium is specified for the core and top material, and the listed gap is 0.04 inches. NGK describes its plugs as often specified as original equipment, but the listing advises researching the application, engine, drivetrain, and quantity needed before purchase. It supplies no specific 4Runner year range.

Skip it if you want a set explicitly matched to a 4Runner year; Sixity Auto’s NGK Laser Iridium listing names 2013–2020 compatibility.

This option fits buyers who specifically want NGK Iridium IX plugs and have verified the application and required quantity. For a 5th-gen 4Runner, the listing’s lack of a named year range makes fit research essential.

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

#9

9. NGK LFR6AIX-11

• Core Material: Iridium
• Weight: 0.27 g

Best for: Wide-heat-range NGK plugs.

Why it ranks #9: The six-pack NGK listing gives iridium construction and 14mm thread diameter, but does not identify 5th gen 4Runner compatibility.

NGK’s stated wider operating heat range is the defining feature of these Iridium IX plugs, offering buyers a plug described as operating across a broader range than ordinary plugs. The six-pack format and published thread dimensions add useful details for owners evaluating a replacement set.

NGK says the plugs operate over a much wider heat range than ordinary plugs, which is the listing’s main operating distinction. The product also claims resistance to carbon buildup and pre-ignition, giving buyers two stated concerns addressed by its design. Its patented triple-gasket sealing process is specifically described as eliminating the possibility of combustion-gas leakage. The six-pack quantity is listed, but no 4Runner model-year application is supplied, so buyers must establish vehicle fit separately.

Skip it if you need an explicitly listed 4Runner year range; Sixity Auto’s NGK Laser Iridium set names 2013–2020 fitment.

This NGK six-pack suits buyers prioritizing the stated heat-range, buildup-resistance, and sealing features. It is not the clearest choice for a 5th-gen 4Runner owner who needs an application explicitly tied to a model year.

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