10 Best Spark Plugs For 4.6 Mustang Reviewed 2025

When I first got my hands on a 4.6L Mustang, I knew the Modular V8 was tough, but I also quickly learned how sensitive it can be to ignition components. A smooth idle, quick throttle response, and avoiding those dreaded misfires—it all comes down to finding the best spark plugs for 4.6 Mustang. Whether you run a ’99 SOHC GT or a newer 3-valve ‘Stang, choosing the right material (copper, platinum, or iridium) and ensuring proper fitment is critical. I’ve put together a hands-on guide reviewing the top options to help you dial in your ignition system for maximum performance.

IMAGE	PRODUCT NAME	AMAZON LINK
	8 pc NGK V-Power Spark Plugs compatible with Ford Mustang…	View on Amazon
	MAS Ignition Coils DG508 and Motorcraft OEM Spark Plugs…	View on Amazon
	A-Premium Double Iridium Spark Plug Compatible with Ford…	View on Amazon
	DG508 Ignition Coil Pack & Iridium Spark Plug SP479 Set,…	View on Amazon
	8 pc NGK V-Power Spark Plugs compatible with Ford Mustang…	View on Amazon
	Iridium Spark Plugs 8 Pack SP515 SP546 Compatible with…	View on Amazon
	Pack of 8 Genuine Motorcraft Spark Plug SP-493 AGSF32PM	View on Amazon
	SP493 Double Iridium Spark Plugs Fit for Ford F150 F250…	View on Amazon
	Ignition Coils DG508 & Spark Plugs for Ford 4.6 F150…	View on Amazon
	Ignition Coil Pack Spark Plugs Compatible with Ford 4.6L…	View on Amazon

8 pc NGK V-Power Spark Plugs compatible with Ford Mustang 4.6L 5.0L V8 1993-2004

NGK’s V-Power line is a fantastic choice if you prioritize a consistent, powerful spark without the high cost of iridium. These are generally standard copper core plugs featuring a unique V-cut in the center electrode, which actually directs the spark better toward the edge of the ground strap. They deliver reliable performance especially suited for the earlier 2-valve SOHC 4.6L engines from 1993 through 2004. This set is a dependable, genuine NGK replacement that brings life back to an aging ignition system.

Key features that stand out:
– V-Groove Technology: Promotes better ignitability and reduced quenching.
– Genuine NGK Parts: Ensures quality and reliable fitment.
– Copper Core Construction: Excellent conductivity for a strong, consistent spark.
– Wide Fitment Range: Specifically covers the older, highly popular 4.6L and 5.0L V8 models.

Pros:
– Excellent conductivity, ideal for modified or forced induction setups (when properly gapped).
– Highly cost-effective replacement option.
– Proven reliability and strong resistance to fouling.

Cons:
– Requires replacement more frequently than platinum or iridium plugs.

Best for: Budget-conscious owners of 1999–2004 Mustang GTs who prioritize raw conductivity and don’t mind shorter replacement intervals.

Expert Opinion: NGK copper plugs are often the go-to for enthusiasts who regularly track their cars or use forced induction, as they maintain a stable spark under extreme cylinder pressure better than multi-tip plugs.

MAS Ignition Coils DG508 and Motorcraft OEM Spark Plugs SP413 Compatible with Ford F-150 Mustang V8 4.6L pack of 8

If your 4.6L Mustang is experiencing misfires and rough idling, it often means you need more than just new plugs—you need coils too. This kit from MAS provides a complete ignition refresh, pairing replacement DG508 coils with Motorcraft OEM SP413 spark plugs. This is a great solution for restoring factory performance and ensuring that all components meet OE standards for fit and function. It takes the guesswork out of matching parts.

Key features that stand out:
– Complete Ignition Kit: Includes 8 ignition coils and 8 spark plugs.
– Motorcraft OEM Plugs (SP413): Ensures factory reliability and specification.
– OE Standard Coils: Built to meet or exceed original equipment specifications (DG508 replacement).
– High Durability: Coils use high heat-resistant compounds.

Pros:
– Excellent value proposition for a full ignition system tune-up.
– Pairing coils and plugs eliminates a common cause of misfires.
– Plugs are typically pre-gapped, simplifying installation.

Cons:
– The quality of the aftermarket coils might not match genuine Motorcraft coils in the long run.

Best for: Mustang owners needing a comprehensive, cost-effective full ignition refresh for their 4.6L V8.

Expert Opinion: When replacing coils, using a quality replacement plug like the Motorcraft SP413 ensures your base performance is correct. This combination is ideal for drivers who want OEM reliability without dealer pricing.

A-Premium Double Iridium Spark Plug Compatible with Ford Explorer 2006-2008, Explorer Sport Trac 2007-2008, Mustang 2005-2008 & Mercury Mountaineer 2006-2008 & Avanti Avanti, 4.6L, Pack of 8

For later model 4.6L Mustangs, especially the 2005–2008 models utilizing the 3-valve engine, finding the right iridium plug is key for longevity. These A-Premium plugs feature a double iridium design, meaning both the center electrode and the ground electrode tip are iridium. This construction ensures maximum lifespan and exceptional ignitability over tens of thousands of miles. They are engineered to replace the infamous SP-514/SP-547 plugs, designed for optimal engine performance in modern 4.6L Modular engines.

Key features that stand out:
– Double Iridium Design: Provides extreme durability and up to 100,000 miles of service life.
– Exceptional Ignitability: Engineered for maximum ignition performance.
– Direct Fitment: Designed specifically for 2005–2008 4.6L V8 applications.
– Optimal Gap Size: Comes pre-set to 0.45 inches.

Pros:
– Industry-leading longevity minimizes maintenance frequency.
– Superior performance and stability under varied operating conditions.
– Reliable replacement for hard-to-find specific factory plugs.

Cons:
– Iridium can be brittle, requiring extra care during installation.

Best for: 2005–2008 4.6L Mustang owners who prioritize long-term durability and minimal maintenance on their daily driver.

Expert Opinion: Double iridium is the gold standard for durability. While performance gains over a new platinum plug may be marginal, the lifespan difference means you’ll save significant time and labor over the vehicle’s life.

DG508 Ignition Coil Pack & Iridium Spark Plug SP479 Set, Compatible with Ford 4.6L/5.4L V8 Engines, Fits F-150, F-250, F-350, Expedition, Crown Victoria, Mustang, Lincoln – High Performance Upgrade

This DG508 coil and Iridium SP479 plug set offers a step up from basic OEM replacements, providing a performance-oriented solution for a full ignition refresh. The high-performance iridium plugs offer enhanced durability and sharper spark delivery than standard copper or platinum options. If you’re looking to eliminate misfires while maximizing your engine’s power and fuel efficiency in one convenient package, this set is a strong contender.

Key features that stand out:
– Iridium Spark Plugs (SP479): Superior ignition performance and longer life.
– Complete Tune-Up Solution: Includes 8 coils and 8 plugs.
– Easy Installation: Direct OEM replacement fitment with pre-gapped plugs.
– Durable Construction: Heat-resistant materials prevent premature failure in coils and plugs.

Pros:
– Immediate improvement in throttle response and smooth idle.
– Iridium plugs maintain stable performance under extreme heat.
– Wide compatibility with many popular 4.6L/5.4L Ford models.

Cons:
– As a performance upgrade, it may be overkill for completely stock, low-mileage vehicles.

Best for: Owners of 4.6L V8s (especially the 2V SOHC pre-2004) seeking a measurable performance upgrade during their routine tune-up.

Expert Opinion: Pairing high-output coils with iridium plugs is smart. The iridium tip handles the higher voltage output and maintains gap integrity longer, translating directly to a crisper engine feel.

8 pc NGK V-Power Spark Plugs compatible with Ford Mustang 4.6L 5.4L 5.8L V8 2003-2014

This is the second V-Power option on our list, covering a wider and later range of Modular V8 engines, including specific 4.6L models up to 2014. Just like the earlier version, these genuine NGK V-Power plugs use a nickel-alloy construction with the V-cut center electrode for excellent sparking ability. While they are a copper-based design, their reliability and lower heat range options make them favorites among drivers who push their engines harder than stock.

Key features that stand out:
– Broad Model Coverage: Fits later 4.6L models, ensuring the right size for newer heads.
– Direct Replacement: Designed for hassle-free installation in the specified vehicles.
– Consistent Spark: Proven V-Power design for reliable combustion.

Pros:
– Ideal for engines running slightly higher boost or mild nitrous (when properly re-gapped).
– Lower cost allows for more frequent inspection and replacement.
– Genuine NGK quality assurance.

Cons:
– Frequent high-temperature use can necessitate slightly more frequent replacement than advertised longevity metals.

Best for: Later model 4.6L owners (2003–2014) who prefer the strong, consistent spark delivery of copper for high-performance or track use.

Expert Opinion: NGK consistently delivers quality and conductivity. While standard copper plugs don’t last as long as iridium, the conductivity is unsurpassed, making them a great choice for maximizing ignition power.

Iridium Spark Plugs 8 Pack SP515 SP546 Compatible with 2004 2005 2006 2007 2008 Ford F150 5.4 Expedition Explorer Mustang F250 F350 F450 & Lincoln Mark LT Navigator & Mercury Mountaineer V8 4.6L 5.4L

The 2004–2008 4.6L and 5.4L 3-valve engines are notorious for their unique, two-piece spark plug design, which can break upon removal. These replacement iridium plugs (SP515/SP546 reference) are specifically engineered to address the fitment challenges of the 3V design. They undergo rigorous quality testing aimed at solving common issues like backfiring, misfiring, and poor fuel economy associated with failing 3V plugs.

Key features that stand out:
– Designed for 3V Engines: Critical replacement plugs for the troublesome 2004-2008 4.6L heads.
– Iridium Construction: Provides longevity and stable high-voltage output.
– Quality Control Focus: Tested extensively to address common ignition failures.
– Includes Worry-Free Warranty: Offers 12 months of guaranteed support.

Pros:
– Essential replacements for specific 3V engine models where fitment is critical.
– Improved reliability and reduction in rough idling/engine jerking.
– Iridium offers great lifespan, reducing the need for repeat plug changes.

Cons:
– Requires careful confirmation of the exact engine date/design before purchase.

Best for: Owners of 2005–2008 4.6L Mustang GTs (3V engine) who need the correct, reliable, one-piece style replacement plugs.

Expert Opinion: For the 3-valve 4.6L, fitment is paramount. Using a modern iridium replacement that adheres to the updated SP515/SP546 standard is highly recommended to avoid future extraction nightmares and ensure maximum engine efficiency.

Pack of 8 Genuine Motorcraft Spark Plug SP-493 AGSF32PM

When it comes to Ford engines, many enthusiasts believe there’s no substitute for Motorcraft. The SP-493 is a Genuine Motorcraft Platinum plug, which was the factory standard for many 4.6L SOHC (2V) engines. Choosing these ensures you are matching your car’s original equipment manufacturer (OEM) specifications perfectly, maintaining factory performance characteristics and protecting potential warranties. Platinum plugs offer a significant lifespan advantage over copper.

Key features that stand out:
– Genuine Motorcraft: Guaranteed OEM quality and exact fitment.
– Platinum Spark Plug: Excellent balance of performance and longevity.
– SP-493 / AGSF32PM: Factory part numbers widely used in 4.6L applications.

Pros:
– Unquestioned reliability and perfect factory fit.
– Longer lifespan than standard copper plugs.
– Easiest choice for maintaining factory stock performance.

Cons:
– Does not offer the extreme lifespan of modern double iridium plugs.

Best for: The Mustang purist or owner who insists on using only genuine OEM parts for their 4.6L SOHC tune-up.

Expert Opinion: If you are running a completely stock engine and plan to keep it that way, Motorcraft Platinum is the benchmark. It’s a proven design that the engine management system is calibrated to handle perfectly.

SP493 Double Iridium Spark Plugs Fit for Ford F150 F250 F350 E150 E250 E350 E450 Crown Victoria Mustang Lincoln Navigator 4.6L 5.4L V8 Replaces# SP479, AGSF22WM (set of 8)

For those who want to upgrade the performance and lifespan of the reliable SP493 platform, this double iridium set is an excellent choice. This plug offers a much longer working life (up to 100,000 kilometers) compared to standard platinum or copper options. By utilizing iridium on both electrode ends, they provide exceptional ignitability, resulting in quicker starts, better acceleration, and superior cold-start performance, all while promoting better fuel economy.

Key features that stand out:
– Double Iridium: Engineered for extended service intervals and enhanced spark stability.
– Replaces Popular Numbers: Direct replacement for SP479 and AGSF22WM.
– Improved Economy: Designed to deliver a consistent, powerful spark for lower emissions and better MPG.
– Wide 4.6L/5.4L Compatibility: Fits many popular Mod Motor applications, including many Mustang years.

Pros:
– Longest possible working life minimizes maintenance.
– Superior performance compared to single platinum plugs.
– Helps ensure a smoother running engine and superior cold starts.

Cons:
– Generic branding means long-term material consistency might not match top-tier NGK or Motorcraft.

Best for: High-mileage 4.6L owners who want to install a quality, long-lasting plug and forget about it for years.

Expert Opinion: The move from platinum to double iridium is a worthwhile upgrade for any daily driven 4.6L. The consistent, stable spark provided by iridium drastically reduces the chance of misfires over the plug’s service life.

Ignition Coils DG508 & Spark Plugs for Ford 4.6 F150 E150 01-08 Expedition 01-04 Explorer 02-05 E250 03-08 Crown Vic 98-08 Mustang GT 99-04, Mountaineer 02-05 Town Car 98-05 Grand Marquis 98-11 SP493

This is a highly specific, comprehensive tune-up kit tailored for the popular 1999–2004 Mustang GT SOHC engine. By pairing replacement DG508 ignition coils with the SP493 style spark plugs (often platinum or high-quality nickel), this package offers everything needed to cure a stumbling or misfiring 4.6L. Crucially, it specifically notes compatibility with the SOHC (2-valve) engine, avoiding the fitment issues associated with the 3-valve heads.

Key features that stand out:
– SOHC Specific: Confirmed fitment for 1999-2004 Mustang GT SOHC engines.
– Full Set of Coils and Plugs: DG508 coils and SP493-reference plugs included.
– Direct Reference: All parts cross-reference key OEM part numbers for compatibility.
– High Value: Great option for an owner performing a complete ignition system overhaul.

Pros:
– Removes the hassle of sourcing compatible coils and plugs separately.
– Highly targeted fitment for the most common 4.6L Mustang GT years.
– Cost-effective method for solving hard-to-diagnose misfire issues.

Cons:
– Only fits SOHC engines; DOHC or supercharged versions require different parts.

Best for: Owners of 1999–2004 Mustang GTs who suspect both coils and plugs are past their prime and need a guaranteed fit.

Expert Opinion: When replacing coils and plugs simultaneously, always use quality dielectric grease on the coil boots. This kit provides an excellent baseline for restoring smooth operation to the SOHC Mod Motor.

Ignition Coil Pack Spark Plugs Compatible with Ford 4.6L 5.4L V8 F-150 F-250 Expedition Crown Victoria Mustang Lincoln Town Car Mercury Explorer E-150 E-250 1997 1998 1999 2000 2001 2002 2003, DG508

Targeting the slightly older range of 4.6L V8s, this package provides a value-packed solution for a full ignition refresh. It includes 8 coil packs (DG508 replacement) and 8 pre-gapped spark plugs designed to meet or exceed OEM specifications. If your Mustang is showing signs of hard starting or poor fuel economy, this affordable combo can be a quick and effective solution, especially for models built between 1997 and 2003.

Key features that stand out:
– Wide Coverage: Specifically hits many early 4.6L V8 applications, including 1999–2004 Mustang GT.
– Pre-Gapped Plugs: Simplifies installation, reducing the chance of improper gap settings.
– Meets OEM Specs: Components are produced under high standards to ensure reliability.
– Solves Common Issues: Designed to eliminate engine misfire, hard starting, and rough idle.

Pros:
– Fantastic budget option for a full coil-on-plug and spark plug replacement.
– Direct replacement fitment for specified years.
– Solves multiple ignition problems simultaneously.

Cons:
– The included spark plug material is not specified, likely standard nickel-alloy/copper, offering shorter life.

Best for: Value-minded owners of older (pre-2004) 4.6L Mustangs who need a complete, budget-friendly ignition tune-up.

Expert Opinion: For older vehicles where the budget is tight, kits like this offer incredible value. However, be prepared to check the gap on the plugs before installation, even if advertised as pre-gapped, to ensure optimal performance.

Comparison and Practical Insights

Choosing the right plug for your 4.6 Mustang hinges heavily on the year of your car and what you demand from it—longevity or performance.

For 1996–2004 (2-Valve SOHC Engines):
These engines are generally simpler and more forgiving.
* Best for Stock/OEM: Stick with Genuine Motorcraft SP-493 (Platinum). They are proven, reliable, and what the engine was designed around.
* Best for Performance/Budget: The NGK V-Power Plugs (Copper) are excellent due to copper’s superior conductivity. Just remember, they need to be swapped out every 15,000–20,000 miles.

For 2005–2008 (3-Valve SOHC Engines):
This is the tricky generation. The long, two-piece plug design is sensitive. Correct fitment is non-negotiable.
* Best Longevity/Durability: Choose the Iridium Spark Plugs SP515 SP546. These plugs are designed to be the updated, one-piece replacements that minimize the risk of breakage during the next removal. The double iridium A-Premium Double Iridium Spark Plug is also a great high-mileage choice for this range.

Choosing the Metal:
* Copper (NGK V-Power): Highest conductivity and best for highly modified, forced-induction engines requiring frequent gap adjustments and changes. Lowest lifespan.
* Platinum (Motorcraft SP-493): Great all-around reliability and lifespan (50,000–60,000 miles). Excellent factory standard.
* Iridium (DG508/SP479 Kits): Extreme longevity (up to 100,000 miles) and excellent stability. Recommended for hassle-free daily drivers.

When to Choose a Coil and Plug Combo:
If your 4.6L has over 100,000 miles and you’ve never replaced the coil packs (DG508), consider a full kit like the MAS Ignition Coils and Motorcraft SP413 Plugs or the DG508 Ignition Coil Pack & Iridium Spark Plug SP479 Set. Replacing the entire ignition system at once is the surest way to eliminate misfire culprits.

Final Verdict: Our Top Picks for the 4.6L Mustang

We’ve reviewed 10 great options, but when it comes down to getting the most reliable spark for your 4.6 Mustang spark plugs, here are the winners based on common owner goals:

The Daily Driver’s Choice (Best Longevity)

The A-Premium Double Iridium Spark Plug (for 2005-2008 3V) or the SP493 Double Iridium Spark Plugs (for pre-2004 2V) take the top spot. They offer maximum durability, ensuring you can drive 80,000+ miles before worrying about replacement, keeping your modular V8 running smoothly and efficiently.

The Performance Enthusiast’s Choice (Best Spark Quality)

Hands down, the 8 pc NGK V-Power Spark Plugs are the best. For those running mild tunes or forced induction, the superior conductivity of the copper core allows for a hotter, more stable spark under high cylinder pressure, essential for extracting maximum power.

The Best Complete Tune-Up Value

If you need a total ignition system overhaul, the DG508 Ignition Coil Pack & Iridium Spark Plug SP479 Set provides excellent value. You get the longevity of iridium plugs paired with new coils, making it a reliable, high-performance solution that cures misfires instantly.

Best Spark Plugs For 4.6 Mustang FAQ

What gap should I use for my 4.6L Mustang spark plugs?

The required spark plug gap depends heavily on your specific 4.6L engine (2V vs. 3V) and whether it is naturally aspirated or modified.
* Stock Naturally Aspirated (2V/3V): Most stock 4.6L engines require a gap between 0.050 and 0.054 inches (or 1.27 to 1.37 mm). Always check the manufacturer’s specification decal under your hood or in your owner’s manual.
* Forced Induction (Supercharged/Turbocharged): If you are running boost, you must reduce the gap, usually down to 0.030–0.035 inches. A tighter gap is necessary to prevent the spark from blowing out under high cylinder pressure.

How often should I replace the spark plugs in my 4.6 Mustang?

Replacement intervals depend on the material of the 4.6 Mustang spark plugs:
* Copper/Nickel (e.g., NGK V-Power): Replace every 15,000–30,000 miles.
* Platinum (e.g., Motorcraft SP-493): Replace every 50,000–60,000 miles.
* Iridium (Single or Double): Replace every 80,000–100,000 miles.

Are iridium spark plugs necessary for a stock 4.6L Mustang GT?

No, they are not strictly necessary, but they are highly beneficial. A standard platinum plug (like the OEM Motorcraft) is sufficient for stock performance. However, iridium plugs offer enhanced durability and a much longer service life, which translates to fewer tune-ups over the life of the vehicle, making them a popular upgrade for daily drivers.

What is the difference between 2-valve and 3-valve 4.6L spark plugs?

The difference is critical for fitment, particularly around 2004–2008.
* 2-Valve (Pre-2005 GT): Uses a standard, shorter plug design (e.g., SP-493) that threads directly into the head.
* 3-Valve (2005–2008 GT): Uses a unique, longer two-piece spark plug (e.g., original SP-514/SP-547 plugs) that is known for breaking off in the cylinder head. Always use the updated, one-piece replacements specifically designed for this head style.

Do I need to replace my ignition coils (DG508) when replacing the spark plugs?

It’s often wise, especially if your 4.6L Mustang has high mileage (over 80k–100k miles) or is experiencing misfires. The DG508 coils are common failure points on these Ford Modular V8s. Replacing both the coils and the spark plugs for 4.6 Mustang simultaneously ensures optimal system efficiency and is a smart preventative measure.

Can I use colder heat range spark plugs in my modified 4.6L V8?

Yes, if your engine is significantly modified (high compression, supercharged, or turbo), installing colder heat range spark plugs is essential. A colder plug transfers heat away from the tip more quickly, reducing the risk of pre-ignition (detonation) under extreme operating temperatures, which is a major concern for high-performance Modular V8s.