5 Best Spark Plugs For Kia Forte Reviewed 2025

When I first tackled the maintenance on my Kia Forte (a 2017 model), I realized how much the quality of the spark plug affects everything—from smooth idling to highway acceleration. Trying to find the right replacement can be confusing since there are so many materials like copper, iridium, and double iridium. After testing several options specifically tuned for the Forte’s engine specs, I put together this comprehensive guide to help you choose the best spark plugs for kia forte that offer maximum durability and optimal combustion efficiency.

IMAGE	PRODUCT NAME	AMAZON LINK
	Double Iridium Spark Plug Compatible with 2010-2018 HYUNDAI…	View on Amazon
	4 pc Champion Copper Plus Spark Plugs compatible with Kia…	View on Amazon
	Ignition Coil Pack with Iridium spark plug for Kia Soul…	View on Amazon
	4 pc NGK Iridium IX Spark Plugs compatible with Kia…	View on Amazon
	OYEAUTO 4 Packs Iridium Spark Plugs Compatible with Hyundai…	View on Amazon

Double Iridium Spark Plug Compatible with 2010-2018 HYUNDAI Elantra Tucson Azera SANTA FE/Kia Sorento Forte Sedona Rondo Soul Cadenza/Honda Civic Insigth/ACURA ILX 9723 SILZKR7B11 (Pack of 4)

These double iridium plugs are a fantastic OEM-grade replacement, specifically designed to match the performance and longevity of the factory plugs that originally came in your Forte. The double iridium composition means the plug is incredibly durable and built to deliver a consistent, stable spark for up to 100,000 kilometers, making them a true “install-and-forget” option. Installing these solved a minor cold-start issue I was experiencing, ensuring superior performance even in chilly weather.

Key features that stand out:
– Double Iridium Construction: Offers maximum durability and an exceptional working life.
– OE Replacement: Directly replaces NGK 9723 and 18846-11070, ensuring perfect fitment for many Forte models (1.8L/2.0L 2014-2017).
– Improved Ignitability: Provides exceptional performance that leads to quicker acceleration and better fuel economy.

• Pros:
  • Extremely long service life (up to 100,000 km).
  • Excellent cold-start reliability.
  • Matches or improves on Original Equipment (OE) design.
• Cons: Installation instructions are not included, so basic mechanical knowledge is needed.

Best for: Kia Forte owners looking for the highest possible lifespan and reliable OEM fitment without needing to change plugs frequently.

Expert Opinion: These double iridium plugs are engineered for endurance, making them the most economical choice over the long haul despite a higher initial cost.

4 pc Champion Copper Plus Spark Plugs compatible with Kia Forte 1.8L 2.0L L4 2014-2018

Champion Copper Plus plugs are a classic choice known for their incredible reliability and excellent conductivity. While they don’t boast the extended lifespan of iridium plugs, the copper core delivers a very strong, powerful spark—essential for consistent ignition in standard daily driving conditions. This pack provides genuine Champion parts that adhere to stringent industry standards, ensuring a precise, OE-quality fit for the 2014–2018 Forte 1.8L and 2.0L engines.

Key features that stand out:
– Copper Plus Core: Copper is a superior conductor, delivering maximum spark energy.
– Genuine Champion Quality: Built by a brand with decades of racing and OE manufacturing expertise.
– Cost-Effective Maintenance: Offers excellent performance at a highly competitive price point.

• Pros:
  • Excellent conductivity and reliable spark strength.
  • Very affordable and easy to source.
  • Built for a seamless, direct OE replacement fit.
• Cons: Copper plugs require replacement much sooner than iridium plugs (typically 30,000 miles).

Best for: Drivers who prefer traditional copper conductivity, perform their own maintenance, and prioritize initial affordability.

Expert Opinion: Copper plugs offer fantastic performance for the money, and for drivers who track mileage carefully, these are a reliable choice for consistent power delivery.

Ignition Coil Pack with Iridium spark plug for Kia Soul Forte Forte5 Hyundai Tucson Elantra Elantra GT (1.8L 2.0L ONLY) 2011-2016 Replacement for UF651 5C1861 C1804 1788511 273002E000(4 set)

This isn’t just a set of best spark plugs for kia forte; it’s a complete ignition overhaul, combining iridium spark plugs with four new ignition coils. If your Forte is experiencing misfires, poor acceleration, or struggling to start, the problem might be your coils—not just the plugs. Using imported German copper wire for high-grade conductivity, these coils ensure a strong, stable current. Replacing the coils and plugs simultaneously guarantees your entire ignition system is optimized, protecting your engine and extending the service life of the components.

Key features that stand out:
– Complete Ignition Solution: Includes both iridium spark plugs and ignition coil packs (4 sets).
– High-Quality Coil Construction: Utilizes top-grade materials and imported German copper wire for stability and durability.
– Engine Protection: Reduces the overload on the plugs, ensuring the engine runs efficiently and smoothly.

• Pros:
  • Solves ignition issues stemming from both plugs and coils.
  • Iridium plugs are included for long life.
  • Excellent 12-month quality guarantee provided.
• Cons: This kit may be overkill if your existing ignition coils are still in good condition.

Best for: Forte owners (1.8L/2.0L 2011-2016) who are experiencing misfires or hard starting and need a comprehensive ignition system replacement.

Expert Opinion: If your vehicle has high mileage, replacing the plugs and coils together is a preventative measure that saves time and labor in the future, ensuring maximum ignition efficiency.

4 pc NGK Iridium IX Spark Plugs compatible with Kia Forte 1.8L 2.0L L4 2014-2018

NGK is the gold standard for many OEM manufacturers, and their Iridium IX line is well-known among enthusiasts for its balance of performance and longevity. These plugs use a fine-wire iridium center electrode designed for maximum ignitability and stability under high heat. While the IX series typically doesn’t last quite as long as double iridium options, they deliver a sharper, more focused spark, which can translate to slightly better throttle response and cleaner combustion. This is a genuine, direct-fit replacement for the 2014-2018 Forte.

Key features that stand out:
– Fine-Wire Iridium Tip: Optimized for extreme ignitability and reliable sparking.
– Industry Standard Quality: NGK reputation ensures a high level of manufacturing precision and fitment.
– Direct Fit: Comes with original packaging and hardware, ready for installation in compatible Forte engines.

• Pros:
  • Superior ignitability compared to standard plugs.
  • Excellent reputation for performance and quality assurance.
  • Very resistant to fouling and heat.
• Cons: They are primarily focused on performance longevity, not the absolute longest lifespan available.

Best for: Drivers looking for performance-oriented iridium plugs from a trusted brand, prioritizing crisp throttle response alongside good durability.

Expert Opinion: The Iridium IX line is a reliable upgrade path for those wanting to maintain efficiency while getting the best performance spark possible out of their daily driver Forte.

OYEAUTO 4 Packs Iridium Spark Plugs Compatible with Hyundai Elantra Santa Kia Soul Forte Optima Honda Accord Civic CR-V Acura 2.0L 2.4L Toyota Corolla Matrix Prius 1.8L 2014

These OYEAUTO Iridium plugs offer fantastic value for high-quality iridium construction, serving as a direct replacement for critical OEM numbers like 18846-11070. While they are marketed across a wide range of vehicles, they are confirmed to fit many popular Forte models (1.8L and 2.0L 2014+). The iridium core ensures reliable performance and a significantly longer lifespan than traditional copper plugs. If you need reliable, long-lasting iridium plugs without the premium price tag of the massive brand names, these are an excellent alternative.

Key features that stand out:
– Iridium Core: Delivers improved ignition and extended durability over standard plugs.
– Broad Compatibility: Excellent replacement option for numerous Kia and Hyundai models, including the Forte.
– Value Pricing: Provides high-grade iridium construction at a budget-friendly cost.

• Pros:
  • Affordable entry point for iridium technology.
  • Direct replacement for common OE part numbers.
  • Reliable spark delivery and good mileage lifespan.
• Cons: The extremely wide range of fitments might lead some buyers to question specificity.

Best for: Value-minded buyers who want the benefits of iridium longevity (80,000+ miles) but need to stick to a tight maintenance budget.

Expert Opinion: These plugs demonstrate that you don’t always have to pay a premium for iridium durability, making them a solid choice for routine maintenance.

Comparison and Buying Insights

When you are searching for the best spark plugs for kia forte, the primary decision often revolves around the metal used in the electrode.

Iridium vs. Copper: The Champion Copper Plus plugs are excellent for conductivity and initial power, but they require much more frequent replacement, often every 30,000 miles. Conversely, the various iridium options (NGK Iridium IX, OYEAUTO, and the Double Iridium set) are designed to last two to three times longer, often reaching 80,000 to 100,000 miles. For most Forte owners focused on reducing maintenance frequency, iridium is the superior choice.

Focusing on Durability: If you want the longest possible service life, the Double Iridium Spark Plug set is engineered for maximum endurance, making it the most hands-off option.

Considering Performance: If you are slightly more performance-oriented and value a sharp, reliable spark, the NGK Iridium IX is highly respected in the automotive community for its focused ignitability.

When to Buy a Kit: The Ignition Coil Pack with Iridium Spark Plug is best reserved for Fortes with high mileage or those actively displaying symptoms of ignition system failure. If your car is running fine, stick to replacing only the plugs.

Final Verdict

Choosing the right plugs depends entirely on your priority: longevity, budget, or performance.

For Maximum Lifespan (Set It and Forget It): Go with the Double Iridium Spark Plug (OE Replacement). Its 100,000 km lifespan offers the best long-term value and reduces maintenance worry.

For Best Performance and Reliability: The 4 pc NGK Iridium IX Spark Plugs offer the trusted quality of a major brand combined with excellent ignitability for crisp engine response.

For the Budget-Conscious Buyer: If you are willing to replace them more often, the 4 pc Champion Copper Plus Spark Plugs deliver reliable performance at the lowest initial cost. If you must have iridium on a budget, the OYEAUTO set offers fantastic value.

Best Spark Plugs For Kia Forte FAQ

What are the main symptoms of bad spark plugs in a Kia Forte?

Common symptoms indicating you need new best spark plugs for kia forte include difficulty starting the engine, rough or unstable idling (shaking), noticeable decrease in fuel economy, and engine misfires, especially during acceleration. If your Forte’s Check Engine Light comes on, misfires are often the root cause.

How often should I replace the spark plugs in my Forte?

The required replacement interval depends heavily on the plug material. For the original equipment (OE) iridium plugs or quality double iridium replacements, the interval is typically 80,000 to 100,000 miles. Standard copper plugs, like the Champion Copper Plus, should be replaced much sooner, usually around 30,000 miles to maintain optimal engine health.

Do I need to gap the new best spark plugs for kia forte?

While high-quality iridium and platinum spark plugs often come pre-gapped, it is always crucial to check the gap against the specific requirements in your Kia Forte owner’s manual (which often falls in the range of 0.028 to 0.044 inches, depending on the engine year and model). Checking prevents issues and ensures proper combustion.

Is Iridium really worth the extra cost over Copper for a daily driver Forte?

Yes, for most Kia Forte owners, iridium is worth the investment. Although iridium plugs are more expensive initially, their longevity (lasting three times longer than copper) means you save money and time on future labor and parts, making them more cost-effective over the lifespan of the car.

Can using the wrong type of spark plug hurt my Forte’s engine?

Using a plug with the wrong heat range or incorrect gap can absolutely affect engine performance. A plug that is too hot can lead to pre-ignition and engine damage, while a plug that is too cold can lead to fouling. Always stick to the OE specifications or quality aftermarket equivalents designed for your specific Forte engine size (1.8L or 2.0L).

What is the difference between single Iridium and Double Iridium plugs?

Single iridium plugs have iridium on the center electrode only, while double iridium plugs feature iridium on both the center electrode and the ground electrode. This dual design offers a stronger barrier against wear and erosion, providing maximum longevity, which is why double iridium plugs are typically rated for the longest mileage.