Maintaining the reliable performance of your 1998 Mazda with the 2.5L engine requires quality components, and the spark plugs are at the heart of the ignition system. The right set can significantly influence engine smoothness, fuel efficiency, and overall responsiveness. With various options available, from standard copper to long-life iridium, selecting the best fit for your vehicle and driving habits is a key maintenance decision.
This professional guide simplifies the selection process by presenting a curated list of ten highly compatible spark plug options. We have compiled products from trusted manufacturers like NGK, Motorcraft, and Denso, ensuring you can find a reliable set to keep your Mazda running smoothly for miles to come. Our detailed breakdown will help you understand the benefits of each type.
Our Recommended Spark Plugs for the 1998 Mazda 2.5L
- 8 pc NGK V-Power Spark Plugs for Mazda B2500
- NGK Spark Plug Wire Set for Mazda B2500 2.5L
- 8 pc NGK Iridium IX Spark Plugs for Mazda B2500
- A-Premium Iridium & Platinum Spark Plugs for Mazda
- A-Premium Iridium Platinum Spark Plugs for Ford & Mazda
- NGK BKR5EIX-11 Iridium IX Spark Plug (4 Pack)
- 4 PCS DENSO PLATINUM T T Spark Plugs – PK20TT
- Pack of 8 Genuine Motorcraft Spark Plug SP-493
- E3 Spark Plugs E3.36 Premium Powersports Spark Plug
- Bosch 9607 Platinum+2 Spark Plug
8 pc NGK V-Power Spark Plugs for Mazda B2500
The NGK V-Power series is a solid and reliable choice for a standard tune-up. These plugs feature a unique v-grooved center electrode designed to promote a more robust flame kernel for improved combustion efficiency. This design can contribute to smoother acceleration and stable idling in your 2.5L engine.
As genuine NGK parts, you are assured of the quality and precise engineering that meets original equipment specifications. This 8-pack provides everything needed for a complete cylinder replacement, making it a straightforward and effective solution for routine maintenance.
NGK Spark Plug Wire Set for Mazda B2500 2.5L
While not a spark plug itself, a high-quality wire set is a critical companion for any plug replacement. This NGK set is engineered to deliver maximum ignition energy from the coil to the plug with minimal electrical loss. Properly functioning wires are essential for preventing misfires and ensuring each new spark plug performs as intended.
Installing a new wire set from a reputable brand like NGK during a plug change is a proactive measure. It helps guarantee a complete and reliable ignition system refresh, protecting your investment in new plugs and maintaining optimal engine performance.
8 pc NGK Iridium IX Spark Plugs for Mazda B2500
For those seeking a performance upgrade with extended service life, the NGK Iridium IX series is an excellent option. These plugs feature a fine-wire iridium center electrode, which is both harder and has a higher melting point than platinum. This allows for a sharper, more consistent spark and superior longevity.
The Iridium IX design requires less voltage to fire, which can reduce the strain on your ignition system. This results in improved throttle response and better overall efficiency. This 8-pack is a direct fit for your 1998 Mazda 2.5L, offering a great balance of performance and durability.
A-Premium Iridium & Platinum Spark Plugs for Mazda
This set from A-Premium utilizes a hybrid design, combining an iridium center electrode with a platinum ground electrode. This combination aims to provide the benefits of both metals: the superior spark characteristics of iridium and the slow wear rate of platinum on the ground electrode. The result is a plug designed for consistent performance over a long service interval.
With a specified resistance of 5000 ohms and a precise gap size, these plugs are engineered for reliable operation. They are listed as compatible with several Mazda models, including the 626 with the 2.5L V6, so it is important to verify your specific engine configuration before purchase.
A-Premium Iridium Platinum Spark Plugs for Ford & Mazda
This is another high-quality option from A-Premium, featuring an iridium center electrode tipped with platinum. This construction is intended to maximize the lifespan and firing efficiency of the spark plug. The fine wire design promotes better ignitability for potential improvements in fuel economy and power.
This pack of 6 is listed for the Mazda B4000 with a 4.0L V6 engine. It is crucial to note that the 1998 Mazda 2.5L is an inline-4 engine, so this specific set is not compatible. It is included here as an example to highlight the critical importance of verifying engine displacement and cylinder count when ordering.
NGK BKR5EIX-11 Iridium IX Spark Plug (4 Pack)
The NGK BKR5EIX-11 is a specific iridium plug model that is often used as original equipment in many modern vehicles. Its Laser Iridium construction provides exceptional longevity and consistent performance. The precise heat rating and pre-gapped design ensure it meets strict manufacturer specifications.
This listing is for a 4-pack, and since your 2.5L engine requires 8 plugs, you would need to purchase two packs. As with any component, it is essential to research the specific application for your vehicle’s engine, trim level, and production year to confirm this is the correct part number.
4 PCS DENSO PLATINUM T T Spark Plugs – PK20TT
Denso is another top-tier manufacturer known for its high-quality ignition components. These Platinum TT plugs feature a platinum tip on both the center and ground electrodes, which helps to minimize gap growth and maintain engine performance over a longer period compared to standard copper plugs.
The twin-tip design is engineered for stable combustion and improved efficiency. This pack contains four plugs, so two sets would be required for your 8-cylinder engine. Always cross-reference the part number 4504 with your vehicle’s requirements to ensure a proper fit.
Pack of 8 Genuine Motorcraft Spark Plug SP-493
Motorcraft is the original equipment supplier for Ford, and since the Mazda B-Series trucks of this era shared platforms with the Ford Ranger, Motorcraft plugs are often a perfect OEM-spec match. These SP-493 plugs are platinum-tipped for extended life and reliable performance.
Using genuine Motorcraft parts ensures that the heat range, thread reach, and gap are exactly as engineered for your vehicle’s engine. This 8-pack provides a complete set for a full replacement, offering peace of mind with factory-level quality and compatibility.
E3 Spark Plugs E3.36 Premium Powersports Spark Plug
E3 spark plugs are built with a patented DiamondFIRE technology that features an edge-to-edge electrode design. This is intended to create a larger flame kernel for a more complete burn of the air-fuel mixture. The manufacturer claims this can lead to increased power and improved fuel economy.
It is important to note that this specific E3.36 model is designed for powersport applications like V-Twin motorcycles, including Harley Davidson engines. It is not listed as compatible with the 1998 Mazda 2.5L engine and is included here to illustrate the wide variety of plug types available for different vehicles.
Bosch 9607 Platinum+2 Spark Plug
Bosch is a globally recognized name in automotive components, and their Platinum+2 series offers a robust design for everyday driving. These plugs feature a fine-wire platinum center electrode and a surface air gap design, which Bosch states helps to improve fouling resistance and provides a consistent spark.
The Platinum+2 plugs are engineered for a balance of performance and service life. As with any component, verifying the specific part number and its compatibility with your 1998 Mazda 2.5L engine’s requirements is an essential step before making a purchase to ensure optimal performance.
Buying Guide: Finding the Right Spark Plugs for Your 1998 Mazda 2.5
When I look for the best spark plugs for a 1998 Mazda 2.5, my first stop is always the owner’s manual. It’s the definitive source for the factory-recommended plug type, which is usually a standard copper core plug. For this engine, you’re likely looking for a specific heat range and thread size that Mazda engineers determined was ideal for performance and fuel economy. Sticking close to this recommendation is a safe bet, but modern plug technology offers some great upgrades.
The main decision point is the plug’s electrode material. You have three common choices:
Copper Core Plugs: These are the standard, budget-friendly option. They conduct electricity very well, which can mean a strong spark. The trade-off is that the copper electrode wears out faster than other materials, so you’ll be changing them more often, typically every 20,000-30,000 miles. If you’re keeping things original and don’t mind more frequent maintenance, these are a solid choice.
Platinum and Iridium Plugs: This is where you see a real upgrade. Platinum plugs are harder than copper and last much longer, often in the 60,000-mile range. Iridium is even harder and has a higher melting point, allowing for a finer center electrode that requires less voltage to create a spark. This can translate to slightly better fuel efficiency and more consistent performance. Iridium plugs are the premium choice and can last up to 100,000 miles or more.
For a 25-year-old engine like the 1998 Mazda 2.5, I also consider the condition of the ignition system. If you have older spark plug wires or a slightly tired ignition coil, a plug that requires a lower voltage to fire (like an Iridium plug) can be a smart move. It puts less strain on the rest of the system.
Finally, think about your driving habits. If this Mazda is a daily driver where you want to “set it and forget it,” a long-life platinum or iridium plug is worth the extra initial cost. If it’s a project car or you enjoy getting your hands dirty with regular tune-ups, a quality copper plug will perform just fine. Always remember to check the gap on new plugs before installation, even if the box says “pre-gapped,” as they can get jostled in transit. A proper gap is critical for a clean burn.
Frequently Asked Questions
What is the factory recommended spark plug for a 1998 Mazda 2.5?
The factory specification is your best starting point. For the 1998 Mazda 2.5L engine, the original equipment manufacturer (OEM) plug was typically a specific NGK or Autolite copper core plug. You can find the exact part number in your vehicle’s owner’s manual. While you can upgrade to longer-life materials, starting with the OEM recommendation ensures compatibility and reliable operation.
Can I use platinum or iridium plugs in my 1998 Mazda?
Yes, you absolutely can, and it’s often a good idea. Your engine’s ignition system doesn’t “know” what material the plug is made from; it just delivers a voltage spike. Upgrading to platinum or iridium plugs provides a longer service interval and can offer a more consistent spark over the life of the plug. This is one of the easiest upgrades you can make for improved maintenance scheduling.
How often should I change the spark plugs in my 1998 Mazda 2.5?
The interval depends heavily on the type of plug you install. For traditional copper plugs, plan on a change every 20,000 to 30,000 miles. If you upgrade to platinum plugs, you can usually go 60,000 miles. For top-tier iridium plugs, 80,000 to 100,000 miles is a common lifespan. Always inspect your plugs during routine service to assess their condition.
What are the symptoms of worn-out spark plugs?
I look for a few key signs that it’s time for a change. The most common one is a rough idle; the engine will feel shaky and uneven when stopped. You might also experience difficulty starting the car, a noticeable loss of power and acceleration (misfires), and a significant drop in fuel economy. If you’re noticing any of these, checking your plugs is a great first step.
Is it difficult to change the spark plugs myself on this engine?
For a mechanically inclined person, it’s a very manageable job. You’ll need a basic socket set, a spark plug socket (usually 5/8″ or 13/16″), a gap tool, and some anti-seize compound. The process involves carefully removing the ignition wires, one at a time, unscrewing the old plug, gapping the new one, and installing it. Just be sure to not over-tighten them. If you’re not comfortable, having a professional handle it is a quick and relatively inexpensive service.
Will new spark plugs improve my gas mileage?
If your old plugs are worn out, then yes, installing new ones will very likely restore your fuel economy to its normal level. Worn plugs cause incomplete combustion, which wastes fuel. While new, high-performance plugs might offer a minor efficiency boost, the main benefit is restoring what was lost due to wear. You won’t see a massive jump from an already well-running engine, but you will prevent it from getting worse.