Ford’s 3.5 EcoBoost engine is a beast. But, like any high-performance engine, it needs the right spark plugs. Using the wrong plugs can cause misfires and power loss. You want your EcoBoost running its best. This guide will help you find the best spark plugs for your ride.
Product Overview / Quick Summary
- Motorcraft SP-548 Spark Plug: OEM replacement, great performance.
- NGK 97506 Iridium Spark Plug: Excellent for tuned engines.
- Denso 5346 Iridium Spark Plug: Good all-around performance and durability.
- Autolite HT1 Spark Plug: Budget-friendly option for stock engines.
- E3 Spark Plugs E3.66: Unique design for enhanced combustion.
Top 5 Best Spark Plugs for 3.5 EcoBoost
1. Motorcraft SP-548 Spark Plug
These are the original equipment plugs for the 3.5 EcoBoost. They are designed to provide optimal performance and longevity. These plugs ensure your engine runs smoothly.
Pros:
- ✅ OEM quality and fit.
- ✅ Reliable performance.
- ✅ Long lifespan.
Cons:
- ❌ Can be more expensive than aftermarket options.
- ❌ Not ideal for heavily modified engines.
- ❌ Gap may need adjustment.
Verdict: Best overall for stock or mildly tuned EcoBoost engines needing a reliable OEM replacement.
2. NGK 97506 Iridium Spark Plug
NGK’s 97506 Iridium plugs are a popular upgrade. They are designed for high-performance applications. These plugs offer excellent spark and durability.
Pros:
- ✅ Improved ignition and throttle response.
- ✅ Excellent for tuned engines.
- ✅ Durable iridium construction.
Cons:
- ❌ Can be pricier than other options.
- ❌ May require professional installation.
- ❌ Might not be necessary for stock engines.
Verdict: Great for modified EcoBoost engines looking for improved performance and reliability.
3. Denso 5346 Iridium Spark Plug
Denso 5346 Iridium spark plugs are known for their quality. They offer a balance of performance and longevity. These plugs are a solid choice for daily drivers.
Pros:
- ✅ Consistent performance.
- ✅ Long lifespan.
- ✅ Good value for the price.
Cons:
- ❌ Not the top choice for extreme performance.
- ❌ Gap needs checking.
- ❌ Can be overkill for completely stock engines.
Verdict: A reliable and durable option for those wanting a performance boost without breaking the bank.
4. Autolite HT1 Spark Plug
These Autolite plugs are a budget-friendly option. They are designed as a direct replacement for stock plugs. These plugs offer decent performance at a lower price point.
Pros:
- ✅ Affordable price.
- ✅ Direct fit replacement.
- ✅ Decent performance for stock engines.
Cons:
- ❌ Not ideal for modified engines.
- ❌ Shorter lifespan compared to iridium plugs.
- ❌ Performance isn’t as high as premium options.
Verdict: Best for those on a budget who need a simple replacement for their stock EcoBoost.
5. E3 Spark Plugs E3.66
E3 spark plugs feature a unique electrode design. They are designed to improve combustion. They claim to provide more power and efficiency.
Pros:
- ✅ Unique electrode design.
- ✅ Potential for improved combustion.
- ✅ Claims of increased power and efficiency.
Cons:
- ❌ Performance gains can be subjective.
- ❌ May not be compatible with all EcoBoost tunes.
- ❌ Can be more expensive than standard plugs.
Verdict: Worth a try for those looking for something different, but results may vary depending on your setup.
Buying Guide
Choosing the right spark plugs for your 3.5 EcoBoost can be tricky. Here are a few things to consider.
Engine Modifications: If your engine is stock, OEM or slightly upgraded plugs are fine. If you have a tune or other mods, you’ll want to use high-performance plugs like the NGK or Denso options.
Driving Style: If you drive aggressively, invest in iridium plugs. They are more durable and offer better performance under stress. For normal driving, standard plugs will suffice.
Budget: Spark plugs range in price. Autolite offers a budget-friendly option. Motorcraft, NGK, and Denso are mid-range to high-end choices.
Heat Range: Using the correct heat range is crucial. A colder plug is better for modified engines. A hotter plug is better for stock engines. Refer to your tuner or a mechanic for the best heat range for your setup.
Gap: Always check and adjust the spark plug gap. A properly gapped plug ensures optimal combustion. Use a spark plug gapping tool and consult your vehicle’s service manual for the correct specification.
FAQs
What happens if I use the wrong spark plugs?
Using the wrong spark plugs can cause misfires, reduced power, and poor fuel economy. It can also damage your engine over time.
How often should I replace my spark plugs?
The replacement interval depends on the type of plug. Iridium plugs can last up to 100,000 miles. Standard plugs typically need replacement every 30,000 to 50,000 miles. Check your owner’s manual for specific recommendations.
Can I install spark plugs myself?
Yes, you can install spark plugs yourself if you have the right tools and some mechanical knowledge. But, if you are not comfortable, it’s best to have a professional do it.
What is spark plug gap?
Spark plug gap is the distance between the center electrode and the ground electrode. This gap needs to be precise for optimal spark and combustion. It’s measured in thousandths of an inch (e.g., 0.030″).
Will changing spark plugs improve my gas mileage?
Yes, replacing worn spark plugs can improve your gas mileage. Old plugs can cause incomplete combustion, wasting fuel.
Conclusion
Choosing the best spark plugs for your 3.5 EcoBoost is important. It keeps your engine running smoothly. Consider your engine modifications, driving style, and budget. With the right plugs, your EcoBoost will perform at its best for years to come. I hope this guide helped you make the right choice!
This site contains affiliate links. As an Amazon Associate, I earn from qualifying purchases. This means if you click on a link and buy a product, we may receive a small commission at no extra cost to you.
