Buyer's Guide & Information

Best Spark Plugs For Gas Mileage Reviewed

Are you wanting to find the best spark plugs for gas mileage? We review some of the top options on the market for a better fuel economy.

The spark plugs in your vehicle are an essential part of the ignition system. Because this system affects your vehicle's fuel economy, you want to find the best spark plugs for gas mileage. We review some of the top options when looking for the best spark plugs for better gas mileage.

Preview

Product

Core Material

Plug Type/Number

Gap Size

Check Price

Bosch Automotive 242230554 9689 Double...

Bosch Automotive 242230554 9689

Iridium

9689

0.039"

NGK BKR7EIX IX Iridium Plug

NGK BKR7EIX IX

Iridium

BKR7EIX

0.028"

E3 Spark Plugs E3.38 Powersports Spark Plug...

E3 Spark Plugs E3.38

Copper

E3.38

0.028"

ACDelco -12680072 41-110 Professional Iridium...

ACDelco -12680072 41-110

Iridium

41-110

0.040"

6 PCSNEW -- DENSO #4503 PLATINUM T T Spark...

DENSO #4503

Iridium

4503

0.040"

Pack of 8 Genuine Motorcraft Spark Plug...

Motorcraft SP-493 AGSF32PM

Platinum

SP-493

0.044"

Autolite HT15 Platinum High Thread Spark...

Autolite HT15

Platinum

HT15

0.052"


Can Spark Plugs Increase Gas Mileage?

Will changing spark plugs increase gas mileage? It can if you are swapping out a fouled-out plug or one with a lot of carbon buildup. Once the spark plug fouls, the gas mileage is significantly impacted as the engine has to work harder to perform. Additionally, any time there is carbon buildup on the plug, the engine fails to burn fuel or burns too much, affecting the fuel economy.


Buyer's Guide to Spark Plugs for Improved Fuel Efficiency

Vehicle Compatibility

Finding the best spark plugs for performance and fuel economy starts with discovering which set is right for your vehicle. The plugs must be compatible with your make, model and year, as well as the number of cylinders your engine has, the displacement, type of fuel system, and the ignition coil.  

Spark Plug Type & Coating

Choosing the best spark plugs for gas mileage requires you to look at the different materials used. Copper spark plugs are the cheapest of the bunch and tend to be what's included in older vehicles, but these don't last very long. Instead, you might prefer to upgrade to platinum, double platinum, or iridium spark plugs. Do iridium spark plugs improve gas mileage? If you are upgrading from worn-out copper plugs, you should notice a significant improvement in fuel economy.

Thread, Nut & Gap Sizes

You need the appropriate spark plug to fit the cylinder. To do this, you first look at the thread size. Using a spark plug with an inaccurate thread or nut size can negatively affect the well-being of your engine. Most modern spark plugs come pre-gapped, but you want to check this measurement to ensure it's what is required by the engine manufacturer. If not, use a spark plug gap tool to create the right measurement.

Heat Specifications

The spark plug heat range shows its thermal capability. It's a number that indicates how hot or cold the spark plug is. Hot spark plugs heat up quickly, while the cold spark plug provides more resistance to heating up. There are various reasons to use either spark plug, making the heat range important.

Life Expectancy

Before installing the best spark plugs for high mileage cars, you want to know how long they should last. If you have to change the plugs every 30,000 miles, you will be doing more tune-ups than the driver who opted to put in plugs with a 100,000-mile service duration.

Warranty

While spark plugs and fuel economy should be at the top of your mind, you have other factors to consider. For one, you don't want to purchase automotive parts from a company that's not reputable. Additionally, you should make sure that there is a lengthy warranty on the plugs for your protection.

Price

Can bad spark plugs cause bad gas mileage? Yes, but how much do you want to spend to correct the problem? To understand the value you get with good spark plugs, consider how much it would cost to replace your engine because of failure. The small price paid for spark plugs is nothing in comparison. Determine the value of the plugs by dividing the cost by the service interval. You can judge various brands by this per-mile price.


7 Best Spark Plugs for Gas Mileage Reviewed

1. Bosch Automotive 242230554 9689

Product Specifications

Core Material

Iridium

Top Material

Iridium

Plug Type/Number

9689

Gap Size

0.039"

How Many

4

You can't ask for much better than a double iridium design, making these the best spark plugs for fuel mileage. With the iridium firing pin and the ground electrode, you can expect service life to reach four times that of comparable copper plugs. The 0.6mm fine wire firing pin is also designed for superior performance and ignitability.

Bosch also uses a 360-degree continuous laser weld fuse to the spark plug for maximum corrosion resistance. Because it is pre-gapped for your specific vehicle, you shouldn't have to worry about anything but getting them installed. From there, you can drive many miles before thinking about the plugs again while you enjoy the fuel savings. With the seven-year performance satisfaction guarantee, we also feel confident marking these the best spark plugs for high mileage vehicles.

It's difficult to find other spark plugs with such exceptional product reviews. The customers can't get enough of the performance these plugs offer. However, you have to pay for this superior construction. In fact, the price per plug is often double that of the cheap models. Still, if you figure out the price per mile, you will find that it works out, considering you don't have to change them as often.

Pros

  • Highly rated
  • 7-year guarantee
  • Double iridium construction
  • Long service life

Cons

  • Expensive

2. NGK BKR7EIX IX

Product Specifications

Core Material

Iridium

Top Material

Copper

Plug Type/Number

BKR7EIX

Gap Size

0.028"

How Many

1 or 4

Does replacing spark plugs increase gas mileage? It could if you upgrade your OEM plugs to these from NGK. This company is a leader in automotive parts, ensuring you get the performance and fuel savings you want. These iridium plugs come with a 6mm center electrode complete with a taper cut ground electrode to offer more protection against fouling, better acceleration and faster starts.

The company also creates the best spark plugs for performance by using a longer insulator nose and corrugated ribs. Beyond this, the triple gasket seal helps eliminate combustion gas leakage. With the high melting point, you get maximum durability against electrical and heat wear, perfect for using in your high-performance motor. With the trivalent metal plating, you can count on the anti-seizing and anti-corrosion properties.

Because this isn't a double iridium plug like the last one, you can expect to pay a little less. Still, that doesn't seem to affect the performance as customers continue to be just as thrilled. With that said, NGK only provides a 60-day warranty, which much not be enough for you peace of mind. Thankfully, the majority of customers don't seem to have a problem with the construction, so it appears worth investing in.

Pros

  • Highly rated
  • Iridium performance
  • Anti-corrosion properties
  • Long service life

Cons

  • Only 60-day warranty

3. E3 Spark Plugs E3.38

Product Specifications

Core Material

Copper

Top Material

Copper

Plug Type/Number

E3.38

Gap Size

0.028"

How Many

1

You need to think about tune-ups for all of your vehicles, not just cars, trucks, and SUVs. Whether you are a power sports enthusiast or you want to hit the open road, you might consider looking for the best spark plugs for motorcycles. High-performance engines need extra care that can only be provided with a well-constructed plug. These E3 plugs increase power, improve emissions, and reduce fuel consumption.

They include DiamondFIRE ground electrodes that are secured to the plug shell with two legs, allowing the heat transfer to be optimized. Plus, the plugs hold up under the vibration received from power sport engines. There is also an edge-to-edge design that concentrates the energy, resulting in quicker and more efficient starts in all conditions.

You can replace the Champion plug in your Honda, Suzuki or Yamaha bike with this plug and receive better fuel consumption. Because the customer reviews are so high, you know you will get exactly what you expect. However, this company only provides a 90-day warranty, which doesn't seem long enough, especially when compared with other manufacturers. The biggest reason to choose E3 for your bike is the company's experience outside the realm of regular vehicles. E3 plugs service a variety of other equipment, such as lawnmowers, watercraft, all-terrain vehicles, and more.

Pros

  • Designed for motorcycles
  • Superior performance
  • DiamondFIRE ground electrodes
  • Vibration-resistant

Cons

  • Only 90-day warranty

4. ACDelco -12680072 41-110

Product Specifications

Core Material

Iridium

Top Material

Copper

Plug Type/Number

41-110

Gap Size

0.040"

How Many

1 or 4

ACDelco is a leader in automotive parts, providing all of the equipment for GM vehicles. However, this particular plug was specifically designed to work in a variety of motorcycle engines. It is constructed with iridium, which provides better engine stability during idling and an overall smooth performance. With the smaller, more efficient electrode design, you can count on improved starting and faster acceleration. 

The iridium fine-wire electrode is made to improve the fuel ignition while also burning away the tip's carbon deposits when they form. These unique functions further ensure you get the best fuel economy possible out of your bike. ACDelco also uses a one-piece suppressor seal to block out any radio frequencies that might affect the electronics on your vehicle.

The biggest perk of buying ACDelco is the price. Even though these are an upgrade from most stock spark plugs, you aren't paying a fortune to get them. Plus, the customer reviews suggest that the plugs respond as expected. The company even puts a one-year warranty on plugs in case there is a problem. However, some people have been unhappy with damage during shipping. It's an issue that could occur with any spark plugs that are shipped, so it's not really a red flag.

Pros

  • Reliable brand
  • Iridium construction
  • 1-year warranty
  • Reasonable price

Cons

  • Some shipment issues

5. DENSO #4503

Product Specifications

Core Material

Iridium

Top Material

Copper

Plug Type/Number

4503

Gap Size

0.040"

How Many

6

Do you want the best for small cars and sedans? Denso offers a solid solution that is also reasonably priced. These platinum TT spark plugs have a twin-tip design that improves ignitability while providing more reliability. These plugs are created with a platinum design and a titanium-enhanced alloy for the ground electrode. This design ensures there is less tip erosion with increased durability.

Both of these metals work together to fight off corrosion for longer life. You can also expect a service life up to 60,000 miles, which isn't as long as some iridium but is longer than most copper plugs. Another unique aspect of the construction is the secondary tip located in the ground electrode, which provides less obstruction of the spark while still maintaining the same gap. That's why many customers switch to this brand after noticing slower acceleration, engine misfires, or poor fuel economy.

Now, you might notice that the company isn't as well-known as some of the other top manufacturers. However, customers have been pleased with the durability and performance. Plus, the company offers a one-year warranty for additional protection against defects. If this fits your vehicle, you can't really go wrong considering the lower price.

Pros

  • Highly rated
  • Reasonable price
  • 1-year warranty
  • Durable construction

Cons

  • Not as well-known

6. Motorcraft SP-493 AGSF32PM

Product Specifications

Core Material

Platinum

Top Material

Copper

Plug Type/Number

SP-493

Gap Size

0.044"

How Many

8

Motorcraft is the brand making Ford parts, so you can trust the construction of these platinum spark plugs. These direct replacements provide the factory performance you are looking for at a lower price. With the higher melting point from platinum, you get better resistance to erosion while receiving superior engine performance. Plus, the plugs are designed to last between 60,000 and 100,000 miles.

Sure, they aren't the top of the line plugs. But, when you figure out the mileage to change spark plugs, you see you are spending very little per mile to run these in your engine. That's what makes them the best value for money option. It's an excellent choice for your everyday driving but might not be the optimal choice if you are regularly towing, hauling, or driving in extreme conditions. In these cases, you might prefer an iridium plug instead.

You can see by the customer reviews that owners have found success upgrading the plugs with this variety. It's possible to receive a boost in fuel economy, especially if you are currently using old or fouled-out plugs. Plus, the company provides a one-year warranty for additional protection. Thankfully, you shouldn't ever need to contact the company due to defects.

Pros

  • Good value
  • Reliable brand
  • 1-year warranty
  • Longer service life

Cons

  • Not for heavy-duty applications

7. Autolite HT15

Product Specifications

Core Material

Platinum

Top Material

Alloy steel

Plug Type/Number

HT15

Gap Size

0.052"

How Many

1

You want to protect your Ford engine, which is why you need to find the top choice. We think these Autolite plugs are the best for 4.6L, 5.4L & 6.8L engines. In fact, they were specifically designed with these engines in mind. The platinum fine wire tip offers the fuel efficiency, improved horsepower, and lower emissions you seek.

Plus, they come with an OE, patented design to provide a superior replacement to your existing equipment. The one-piece ground shield strap works to provide even better heat transfer. High-strength steel technology is also utilized to work with a special socket tool and allow for a quicker replacement. Autolite is a top brand that is trusted by many, and you could be the company's next customer.

While this plug provides a lot of upgrades, some people might not feel it is worth the additional money. However, you need to consider what it would cost if your Ford engine required a replacement because you choose the cheaper plugs instead. Is that savings worth the cost down the road? It's best to put a few more dollars into maintenance today than to have a costly repair bill later. Who better to trust than the manufacturer that understands Ford engines?

Pros

  • Meant for Ford engines
  • Trusted manufacturer
  • 1-year warranty
  • Patented design

Cons

  • Expensive

When It's Time to Replace Spark Plugs

Spark plugs and fuel consumption are at the top of your mind, but there are other reasons you should consider changing these parts. Ideally, you will perform a tune-up during the recommended interval provided by your automaker.

Aside from this, if you notice that the vehicle has a rough idle, is giving you trouble when starting, or has started misfiring, you might consider swapping out the plugs. Some of the best spark plugs can go up to 100,000 miles without needing a replacement.


How to Clean & Change Spark Plugs

Can changing spark plugs improve gas mileage?  Yes, but sometimes you only need to clean them off. Here are some tips for cleaning and changing your spark plugs.

  1. 1
    Locate the spark plugs. Typically, there is one spark plug per cylinder, but some models use two.
  2. 2
    Use compressed air to clean the area around the spark plugs. If dirt falls into the cylinder, you could ruin your engine.
  3. 3
    Remove the spark plugs one at a time.
  4. 4
    Clean the plug with 220-grit sandpaper on the electrode.
  5. 5
    Spray brake cleaner on the plug and wipe it down.
  6. 6
    If that doesn't do the trick, you should install new plugs.

If you want to visually see how to clean spark plugs, consider watching this YouTube video.


People Also Ask (FAQs)

Can bad spark plugs cause bad gas mileage?

The more important question is - can spark plugs increase gas mileage? Yes, if you are upgrading from fouled-out dirty plugs, or if you choose to upgrade to a model that provides more performance.

What causes spark plugs to wear out?

The spark plugs become overheated, which wears down the electrode. There could also be oil contamination if oil seeps in, which fouls the tip. Furthermore, carbon buildup can lead to premature failure, which is caused by dirty injectors or a clogged air filter.

Does changing spark plugs always increase gas mileage?

No, if you change the spark plugs for the same type and the previous ones were still functional, you probably won't notice any difference in the fuel economy. The performance increase is noticed when you upgrade to a better brand or swap out the fouled plugs.

How much does it cost to replace spark plugs?

Your tune-up cost depends on the make and model of your vehicle, as well as the type of plugs you plan to install. If you plan to do the replacement yourself, you will spend less than $10 a plug for most varieties. However, if you need a professional for the installation, you will have to pay them hourly for the job.

How many miles can spark plugs last?

Copper spark plugs have the shortest lifespan, typically around 30,000 miles. However, if you upgrade to platinum or iridium spark plugs, you might be able to get 100,000 miles out of some varieties. Check your owner's manual and instructions from the plug manufacturer to determine the best mileage for spark plug replacement.

Are spark plugs universal to all engines?

No, you need spark plugs that work with your engine. Spark plugs are available in various sizes, each featuring a different gap and made from various metals.

Where is the best place to buy spark plugs that increase gas mileage?

Whether you are purchasing spark plugs or engine tuners for more performance and optimization, we recommend shopping with Amazon. This site provides a compatibility tool to check if the accessories work with your vehicle.


Conclusion

What spark plugs are best for better gas mileage? While it truly depends on what vehicle you drive, we prefer the Bosch Automotive 242230554 9689. With the double-iridium construction, you get the longest service life possible while receiving maximum performance.

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