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When your 2015-2020 Ford F-150 runs rough, stumbles on cold starts, or shows a misfire code, a correct spark plug choice can restore smooth operation and consistent fuel burn. This guide focuses on the specific plug types and attributes that suit the 3.5L and 5.0L engines used across 2015–2020 F-150 models, with a curated shortlist of six top options for this year range. You will find practical notes on durability, ignition performance, and thermal characteristics so you can pick a plug that matches your driving and maintenance preferences. The guide explains why each shortlisted option made the cut and what to expect when you install new plugs in your F-150.
Looking for other parts? See all Ford F-150 parts & accessories.
Top Picks at a Glance
| Best Quality Built to a higher standard if you want something more solid | Sixity Auto NGK Iridium IX Spark Plugs, 6-Pack |  |
| Best Value The sweet spot between price and what you get | A-NAFTULY 94374 Iridium Spark Plugs, 6-Pack |  |
| Best Budget The cheapest option that still gets the job done reliably | BDFHYK Iridium Spark Plugs 6-Pack |  |
| Highest Rated A top-rated pick with lots of positive feedback | Motorcraft SP548 Spark Plug Set of 8 (Ford OEM) |  |
| Most Popular A crowd favorite that many people choose with confidence | ECCPP Ignition Coil Pack with Iridium Spark Plugs, Set of 6 |  |
| Best Seller A high-volume bestseller chosen again and again | BOSCH OE Fine Wire Double Iridium Spark Plugs (Pack of 4) |  |
Sixity Auto NGK Iridium IX Spark Plugs, 6-Pack
| Manufacturer | Sixity Auto |
|---|---|
| Brand | Sixity Auto |
| Applicable engine | 3.5L V6 |
| Quantity | 6 pack |
These NGK Iridium IX spark plugs are a direct-replacement iridium option supplied in a six-pack for the 3.5L V6 F-150 EcoBoost family. Iridium tips and a tapered ground electrode promote stronger, more consistent ignitions and better throttle response compared with basic copper plugs, and the listing notes a copper core for improved heat transfer. Buyers will install them during routine tune-ups or when chasing misfires; several users report the plugs arrived pre-gapped and cleared misfire and acceleration issues. The practical benefits are improved ignitability, longer service life than standard plugs, and generally stable performance under normal driving and towing loads. Downsides to consider are mixed reliability reports from some buyers and the need to verify correct gap and fitment before install; as with any replacement plug, installation torque and connector handling matter to avoid damage. For someone focused on restoring sharp response and longer intervals between changes, these deliver the expected iridium advantages at a replacement-plug level.
Best for: Drivers who want sharper throttle response and longer-lasting spark plugs for performance-oriented driving and who are comfortable checking fitment and gap before installation.
Less Ideal for: Buyers seeking a guaranteed OEM brand source or those unwilling to inspect and gap plugs prior to fitting should consider dealer-sourced factory replacements instead.
- Iridium-tipped electrode and tapered ground design for improved ignitability and throttle response
- 98 percent copper core for efficient heat transfer and stable temperature control
- Sold as a six-pack to replace all cylinders in one service
- Reported pre-gapped on arrival, reducing initial setup time
- Some user reports of premature failure leading to misfires
- Fitment and gap still require verification before installation
Verdict: If you want improved ignition performance and longer intervals between changes for a 3.5L F-150, these iridium plugs deliver performance-oriented gains in a convenient six-pack.
A-NAFTULY 94374 Iridium Spark Plugs, 6-Pack
| Included Components | 6 Pack Iridium Spark Plugs |
|---|---|
| Thread Size | 5/8 |
| Gap Size | 0.04 Inches |
| Core Material | Iridium |
These A-NAFTULY 94374 iridium spark plugs are a direct-replacement option intended for 3.5L V6 Ford F-150s and other compatible Ford and Lincoln engines. They use an iridium center electrode and platinum core to deliver a concentrated spark and longer wear life versus standard copper plugs. Installation is straightforward for routine tuneups: reach and thread size match common Ford spark plug cavities and the plugs come pre-gapped to 0.032 to 0.04 inch depending on listing details, so most users can install them with basic hand tools and a torque wrench. Real-world benefits reported by owners include smoother idling, fewer misfires, and modest fuel-economy gains after replacement. Build quality appears consistent with typical aftermarket iridium plugs, though a small number of buyers reported fragile porcelain that cracked during installation, so careful torque and using anti-seize as recommended are advisable. These plugs are best when you want a longer-lasting, performance-oriented replacement without paying OEM-brand premiums, but exercise caution during installation to avoid damage to the insulator.
Best for: Practical buyers who want a durable, longer-life replacement that improves day-to-day drivability without paying OEM prices and who are comfortable performing or supervising a standard spark plug change.
Less Ideal for: Buyers who want guaranteed factory-brand parts or who prefer professional installation-only solutions may prefer an OEM-branded plug or dealer service instead.
- Iridium center electrode for extended service life compared with standard copper plugs
- Pre-set gap suitable for many compatible Ford/Lincoln engines, reducing setup time
- Vehicle-specific fit and common 5/8 hex/thread size simplify installation
- Users report improved idling and reduced misfires after replacement
- Some reviews mention cracked porcelain during tightening, indicating careful installation is required
Verdict: Choose these iridium plugs if you want a cost-effective, longer-lasting replacement that improves idle smoothness and reduces misfires on 2015–2020 Ford F-150 3.5L engines.
BDFHYK Iridium Spark Plugs 6-Pack
| Unit Count | 6.0 Count |
|---|---|
| Item Type Name | Iridium Spark Plug |
| Core Material | Ceramic |
| Top Material Type | Nickel |
| Automotive Fit Type | Vehicle Specific Fit |
These BDFHYK iridium spark plugs are a budget-focused replacement set sold in a pack of six for V6 Ford engines like the 3.3L, 3.5L and 3.7L used across F-150 and related models. They use a fine iridium center electrode and ceramic insulator to deliver improved ignition sensitivity and a manufacturer-claimed factory-level fit. In typical use you install them as a direct replacement to restore spark quality, smoother idling, and better throttle response compared with worn stock plugs. The set is convenient for homeowners who want to do a full bank service in one purchase. Customer feedback is mixed which suggests performance can vary between units and some buyers reported misfires or early failure, so expect variability in durability. Packaging and accessories are basic but the parts themselves are compatible with the listed OE numbers. If you need a low-cost iridium option to refresh aging plugs and get near-factory performance without paying premium-brand prices, this set is a practical choice, though results may not match higher-end branded spark plugs for long-term longevity.
Best for: Buyers looking to refresh all spark plugs on a V6 F-150 or similar Ford vehicles on a tight budget who prioritize upfront cost and convenience over long-term brand reliability.
Less Ideal for: Drivers seeking the longest-lasting, top-tier iridium plugs or those who rely on consistent, dealer-grade parts for high-mileage or performance builds should consider premium branded options instead.
- Sold as a complete 6-pack convenient for replacing all plugs on V6 engines
- Iridium center electrode for improved ignition sensitivity compared with standard plugs
- Ceramic insulator construction aimed at good strength and insulation
- Designed to match common OEM part numbers for direct, vehicle-specific fit
- Mixed user reports on longevity and occasional misfires after installation
- Basic packaging and variable quality control compared with premium brands
Verdict: A cost-conscious six-pack of iridium plugs that fits V6 Ford engines and offers improved ignition performance for buyers prioritizing value over premium durability.
Motorcraft SP548 Spark Plug Set of 8 (Ford OEM)
| Manufacturer Part Number | SP548 |
|---|---|
| Compatible with Vehicle Type | Car, Truck |
| Core Material | Copper |
| Top Material Type | Alloy Steel |
These Motorcraft SP548 plugs are the factory-quality replacement designed for select Ford 5.0L and 5.2L V8 engines from the mid-2010s. Sold as a set of eight, they use copper core construction with platinum-tipped electrodes to match factory combustion behavior and recommended service intervals. In practice they restore correct gap and ignition consistency after worn plugs, which reviewers report improves idle smoothness and overall drivability on high-mileage F-150s. The vehicle-specific fitment simplifies installation by matching thread and reach to the original parts, though access to rear plugs on some V8 layouts can still be tight and may require patience or basic tools. These are a straightforward option for routine maintenance or replacing aged plugs to maintain reliability and engine performance; they are not a performance upgrade for modified engines but prioritize durability and correct operation for stock setups.
Best for: Buyers wanting a reliable, factory-equivalent replacement to maintain engine smoothness and longevity on mid-2010s Ford F-150 V8 engines.
Less Ideal for: Drivers seeking high-performance or extended-life iridium plugs for modified engines should consider performance-oriented alternatives.
- Factory-quality fit and construction matched to Ford 5.0L/5.2L V8 engines
- Platinum-tipped electrodes for consistent spark and longer life than plain copper
- Sold as a complete set of eight for full V8 replacement jobs
- Restores factory gap and idle smoothness on high-mileage engines
- Not intended as a high-performance or extended-life iridium upgrade
Verdict: Choose these Motorcraft SP548 plugs when you want a dependable, factory-matched replacement to keep a 2015–2020 F-150 V8 running smoothly.
ECCPP Ignition Coil Pack with Iridium Spark Plugs, Set of 6
| Included components | 6 ignition coils and 6 iridium spark plugs |
|---|---|
| Compatible with Vehicle Type | Car, Truck |
| Connector Gender | male |
| Automotive Fit Type | Vehicle Specific Fit |
| Reference number | FT4Z12029A, UF773 |
This ECCPP kit bundles six ignition coils with six iridium spark plugs for direct-fit replacement on compatible Ford and Lincoln V6 models. It is intended for bolt-on installation using the factory-style connector and mounting, so a DIYer or technician can swap all six coils and plugs without modification. Notable features include vehicle-specific fit labeling, a stated match to reference numbers such as FT4Z12029A, and iridium plugs that aim to improve long-term spark consistency. In practice the kit offers a cost-effective way to refresh an ignition system that is producing misfires, rough idle, or poor throttle response, and several users report straightforward installation and immediate improvement. Limitations to be aware of are mixed historic feedback on longevity across different vehicles and occasional fitment mismatches if the wrong vehicle variant is selected, so confirm compatibility before installation. Overall this is a budget-friendly, complete coil-and-plug option for restoring V6 ignition performance when you need a full-bank replacement.
Best for: Buyers who prioritize social proof and cautious value choices and want a full-bank, do-it-yourself replacement that matches factory connection style for certain 2015–2020 Ford V6 applications.
Less Ideal for: If you need guaranteed long-term OEM-level longevity or have a non-V6 Ford F-150 configuration, consider higher-cost manufacturer-branded coils or verify a part designed for your exact engine variant.
- Complete kit includes six coils plus six iridium spark plugs for a full-bank replacement
- Factory-style connector and bolt-on installation for direct swap-in without modification
- Designed to meet vehicle-specific reference numbers for easier fitment checks
- Iridium plugs provide more durable electrode life and more consistent spark than basic copper plugs
- Some reviewers report occasional fitment errors or premature failures on certain vehicles
Verdict: A complete, budget-focused coil-and-plug kit that restores V6 ignition performance with direct-fit installation for the specified Ford/Lincoln applications.
BOSCH OE Fine Wire Double Iridium Spark Plugs (Pack of 4)
| Thread Size | M14x1.25 |
|---|---|
| Compatible with Vehicle Type | Car, SUV, Truck |
| Core Material | Iridium |
| Automotive Fit Type | Vehicle Specific Fit |
These Bosch double iridium spark plugs are built as direct, factory-quality replacements intended for modern gasoline engines, including select 2015–2020 Ford F-150 applications with matching thread and electrode design. The ultra-fine iridium firing pin and iridium ground inlay improve ignitability and durability, which can reduce required ignition voltage and help smooth starting and combustion. They come pre-gapped at the factory and use nickel-plated rolled threads to resist corrosion and ease removal, so installation is straightforward and anti-seize is not needed. In everyday use they deliver longer service life than copper plugs and may reduce misfires or rough idling on engines that need new plugs. Important limitations are that correct fitment depends on engine variant and coil design, so you must verify the exact application before buying, and some users report minor tip adjustment needed in rare cases to avoid arcing. For a maintenance-minded buyer the plugs offer low-risk, long-lasting replacement performance when matched to the correct F-150 engine configuration.
Best for: A buyer who wants a reliable, low-risk factory-quality spark plug replacement for routine maintenance on a 2015–2020 Ford F-150 and values durability and straightforward installation.
Less Ideal for: Drivers seeking performance tuning or power gains beyond factory specifications should consider purpose-built performance plugs or consult a tuner rather than this OE-style replacement.
- Double iridium center and ground electrodes for extended life and improved ignitability
- Ultra-fine laser-welded firing pin reduces voltage requirement and aids consistent ignition
- Pre-gapped from factory for ready installation
- Nickel-plated rolled threads resist corrosion and remove easily without anti-seize
- Fitment varies by engine; must confirm compatibility with the specific F-150 engine variant
Verdict: Choose these Bosch double iridium plugs for a dependable, factory-quality replacement that maximizes service life and reliable ignition on supported 2015–2020 Ford F-150 engine variants.
Choosing the Right 2015-2020 Ford F-150 Spark Plug: Key Factors to Consider
Electrode Material and Longevity
Electrode composition determines service life and stable spark performance. Iridium and platinum alloys offer longer life and more consistent gap retention than basic copper cores, which can wear faster and cause performance decline over typical service intervals.
For the 2015–2020 F-150, longer-lasting electrodes reduce how often you need to drop the spark plugs, which is especially useful if you tow or rack up highway miles. Better materials also maintain a smaller, sharper spark that improves combustion efficiency and reduces misfire likelihood as the plug ages.
Heat Range and Operating Temperature
Heat range controls how quickly a plug sheds combustion heat and resists fouling. A plug running too hot risks pre-ignition and electrode erosion, while one running too cold will accumulate deposits and foul, causing misfires.
Select a heat range suited to your engine load profile. If you frequently tow or drive at sustained high speeds, choose a plug with a heat range that tolerates higher combustion temperatures. For mostly city driving, a slightly colder-running plug can help avoid overheating the electrode while still resisting deposit buildup.
Correct Fitment and Thread Reach
Thread length, seat type, and reach must match the engine's cylinder head to ensure proper sealing and correct electrode position in the combustion chamber. An incorrect reach can change mixture flow around the electrode and harm performance or cause engine damage.
Always confirm threads per inch, gasket or tapered seat type, and reach against the F-150's factory specifications for your engine so you maintain proper combustion chamber geometry and avoid mechanical interference with the piston or valves.
Gap Specification and Stability
The spark plug gap influences ignition voltage requirements and spark energy delivery. A gap that is too wide can increase misfires under load, while an overly narrow gap may reduce combustion efficiency and throttle response.
Some plugs arrive pre-gapped to factory specs, while others require careful gapping. Choose plugs that retain gap under thermal cycling and pick a gap that matches the engine's ignition system capability and driving conditions for reliable starting and stable idle.
Resistance to Fouling and Deposits
Plugs that resist fouling maintain consistent combustion across different operating conditions. Oil contamination, carbon buildup from rich mixtures, and additives in fuel can all cause deposits that dampen spark energy and trigger misfire symptoms.
For an F-150 that sees stop-and-go driving, short trips, or occasional heavy load, choose plugs formulated to resist fouling so idle smoothness and cold-start performance remain reliable between service intervals.
Ignition Performance Under Load
How a plug performs during heavy throttle, towing, or uphill driving affects drivability and emissions. A plug that delivers a stable, high-energy spark under high cylinder pressure reduces the chance of detonation or misfire and improves throttle response.
Evaluate plugs based on expected engine load and your typical driving. Plugs designed for consistent high-voltage performance are usually a better fit for owners who frequently haul heavy loads or tow trailers with their F-150.
Common Spark Plug Symptoms and What They Tell You
Recognizing symptoms helps pinpoint whether plugs are the likely cause. Rough idle, hesitation during acceleration, reduced fuel economy, or a persistent misfire code often indicate aging or fouled plugs. A pronounced stumble only on cold starts points to electrode wear or improper heat range.
Pay attention to where a misfire appears. Intermittent misfires under high load can indicate electrode erosion or a gap that has widened with use, while steady misfires at idle may point to fouling. Use symptom patterns together with visual inspection of removed plugs to determine the root cause.
- Rough idle: often carbon buildup or worn electrodes
- Hard cold start: weakened spark energy or incorrect heat range
- Stumble under load: widened gap or electrode erosion
- Poor fuel economy: incomplete combustion from weak spark
Preparing for a Spark Plug Replacement on a 2015–2020 F-150
Work on a cool engine and disconnect the battery if you will be handling ignition components. Gather the correct tools: a torque wrench, the right spark plug socket with an extension, and a gap tool if adjustments are needed. Clean the area around each ignition coil before removal to prevent debris falling into the cylinder.
Keep replacement plugs and any new ignition boots organized by cylinder so you do not mix them up. Note manufacturer-specified torque and thread engagement to avoid crossthreading. Applying a small amount of anti-seize is generally unnecessary on modern plated plugs unless specifically recommended for your plug type.
- Use the specified torque to prevent damage
- Replace one plug at a time to maintain firing order
- Inspect ignition boots and coils for cracking or oil contamination
Gapping and Verification: Practical Tips
Confirm the correct gap specification before installation and verify the plug arrives within tolerance. Some plugs are pre-gapped to factory numbers but can shift in shipping. Use a reliable gap tool to check and adjust gently, avoiding damage to the electrode.
After installation, run the engine and monitor for new noises or check-engine lights. If a misfire persists, recheck gap, torque, and coil condition. For engines with high-voltage ignition systems, avoid excessively wide gaps that the coil cannot consistently bridge.
- Verify gap matches manufacturer or service manual specs
- Adjust gaps carefully with a proper tool
- Recheck torque after a short drive to confirm seating
Heat Range Choices for Different Driving Styles
Selecting the right heat range depends on duty cycle. Owners who regularly tow or carry heavy loads generate higher combustion chamber temperatures and should favor plugs with a heat range that runs slightly cooler to avoid pre-ignition. Conversely, vehicles used mainly for short trips may benefit from a warmer-running plug to resist fouling.
If you change heat range from stock, do so conservatively and monitor engine behavior. Watch for signs of overheating or increased deposit accumulation and be prepared to revert to the OE-recommended range if problems arise.
- Towing and heavy loads: consider a colder heat range
- Short trips and city driving: a warmer range can reduce fouling
- Make changes in small steps and monitor engine response
When to Inspect or Replace Spark Plugs
Inspect plugs at regular intervals aligned with service schedules or when symptoms appear. Visual cues include rounded or eroded electrodes, heavy carbon deposits, or oil contamination. Even if the engine appears fine, plugs past the recommended interval should be replaced to avoid gradual performance loss.
If you experience recurring misfires, increased fuel consumption, or persistent cold-start hesitation, prioritize inspection. Replacing spark plugs is a relatively low-effort maintenance item that can resolve a wide range of drivability issues when done correctly.
- Follow service interval recommendations for inspection
- Check plugs anytime a misfire code returns
- Inspect boots and coils during plug changes
Still looking for the perfect fit?
Select your Ford F-150 configuration to see the most relevant Spark Plugs recommendations
How We Chose the Best 2015-2020 Ford F-150 Spark Plug
We evaluated candidate spark plugs against criteria that matter for 2015–2020 Ford F-150 owners and the engines fitted to those model years. Key evaluation points included material and longevity, focusing on electrode composition and estimated service life; ignition performance under load, with attention to throttle response and combustion quality; cold-start and misfire behavior, which is crucial for diagnosing rough idle or starting hesitation; heat range compatibility to ensure plugs run neither too hot nor too cold for typical highway and towing duty; and direct-fit specifications to match thread reach, seat type, and gap requirements. We prioritized plugs that balance longevity and ignition quality rather than extreme specialty race parts. Durability and resistance to fouling were weighted heavily because many F-150 owners tow or drive long highway miles. We excluded plugs intended solely for high-compression or heavily modified racing engines that require aftermarket tuning. The final list reflects options that meet OE-style fitment and the thermal characteristics appropriate for the stock engines used in 2015–2020 F-150s.
Our full evaluation process is outlined in our review methodology.
FAQ
How often should I replace spark plugs in a 2015–2020 F-150?
It depends on the plug material and driving habits. Iridium or platinum plugs often last much longer than copper cores, but you should still inspect them at regular service intervals and replace them according to your service manual or when symptoms like misfire or rough idle appear.
Can a worn spark plug cause a cold start misfire on my F-150?
Yes. Worn electrodes or a gap that has widened can reduce spark energy during cold cranking and cause hesitation or misfire. Incorrect heat range or fouling from short trips can also contribute to cold-start problems.
Should I change the spark plug gap when I replace plugs?
You should verify the gap and adjust it if it is outside the specified tolerance. Some replacement plugs come pre-gapped to factory settings, but shipping and handling can alter the gap, so a quick check before installation is good practice.
Are higher-end plugs like iridium necessary for my F-150?
Higher-end materials typically offer longer service life and more stable gap retention, which can be beneficial if you want extended intervals between changes or need robust cold-start performance. Whether they are necessary depends on your mileage and driving demands.
Will a different heat range improve towing performance?
Potentially. A plug that runs slightly colder can help when the engine sees sustained high loads during towing by reducing the risk of pre-ignition. Any change from the OE heat range should be made conservatively and monitored.
What should I check if a misfire persists after changing plugs?
Reinspect gap, torque, and plug seating, and check ignition coils and wiring. Persistent misfires can also stem from fuel or compression issues, so rule out those systems if ignition components check out.
Final Verdict
Prioritize correct fitment, the right heat range for your driving style, and a durable electrode material when choosing spark plugs for a 2015–2020 Ford F-150. These factors directly affect cold-start behavior, misfire resistance, and service interval spacing. Balance longevity against ignition performance based on whether you mostly tow, haul, or drive around town. Make decisions conservatively: match thread reach and seat type precisely, verify gaps, and monitor engine response after installation. With those priorities in mind, you can select plugs that restore smooth idle, reliable starting, and steady performance under load.
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