Best Spark Plugs for Gas Mileage in 2020 (Reviews and Guide)

I remember a while back I couldn’t even go on road trips with my car because it used to consume so much gas, it was ridiculous. It took me a couple of months before I figured out that I needed to replace my spark plugs and the results were amazing after I replaced them with genuine spark plugs.

A good spark plug works efficiently throughout enabling your motor vehicle’s engine to run smoothly both on idle and even when in motion. It is important to note that a proper air fuel mixture in the combustion chamber of an engine is very crucial for each and every vehicle on the road. However, this is not possible unless your vehicle has among the best recommended spark plugs that will offer you great performance, durability, reliability and good fuel economy.

Comparison Table for the Best spark plugs for gas mileage

Brand	Material	Check on Amazon
Autolite HT15 Platinum High thread	Platinum	Buy here
NGK 6619 Iridium	Iridium	Buy here
Denso 4504 PK20TT	Platinum	Buy here
Bosch ZGR6STE2	Copper	Buy here
NGK 4929 standard	Copper	Buy here
Bosch X5DC	Copper	Buy here
NGK BKR7EIX Iridium IX	Iridium	Buy here

Here are the Best spark plugs for gas mileage

Autolite HT15 Platinum High Thread Spark Plug

This spark plug comes with a platinum fine wire tip which counters any form of gap erosion which notably improves the fuel economy of your vehicle. The platinum tip also enables the vehicle to have lower emissions which is of benefit to our environment as well. In addition to this, its design resembles an OEM spark plug which is very reliable and enables great performance from the engine consistently.

Specs

• Platinum fine wire tip.
• One-piece ground shield strap.
• High Strength Steel technology.
• Original Equipment design.

The Autolite HT15 Platinum spark plug consists of a one piece shield ground strap design which makes full use of the face of the spark plug shell as an ignition ground. This feature improves heat transfer which is ideal even for engines that emit a lot of heat. Its steel technology is machined to increase its strength which makes the spark plug very durable and work efficiently giving you more gas mileage throughout. This spark plug is specifically made for these specific 3- valve Ford engines i.e the 4.6L, 5.4L and 6.8L.

Pros

• It increases the performance of the engine.
• Comes with two platinum alloys.
• Great durability.
• Improved ignition power focus.

Cons

• Specified for a very limited number of engines.

Verdict

These spark plugs are made to offer greater performance than original equipment Manufacturer spark plugs which guarantees you efficiency and durability. If you own a Ford that has the 3-valve engine system, then this spark plug is a very good choice.

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NGK 6619 Iridium IX Spark plugs

This high quality spark plug is made up of Iridium which improves its longevity as compared to copper and platinum spark plugs. The iridium center electrode is a fine wire that efficiently improves the fuel economy of your vehicle and enables the engine to run smoothly throughout.

Specs

• Fine wire center electrode.
• Iridium alloy.
• Copper core.
• Alumina silicate Ceramic insulator.

A trivalent metal plating on the spark plug prevents it from any form of rust increasing durability as the spark plug will never seize due to corrosion. In addition to this, the corrugated ribs on the spark plug prevents discharge of sparks between the terminal and metal shell which helps in maintaining a reliable air to fuel mixture consistently. This also improves on fuel economy because the engine will be running efficiently. The core on the spark plug also helps in removal of excessive heat. The NGK 6619 Iridium IX spark plugs guarantee you improved performance and torque from your engine as they always deliver a proper air to fuel ratio consistently. These spark plugs are ideal for high performance engines.

Pros

• It offers high durability.
• It provides optimal air to fuel ratio consistently.
• Made up of high quality material.
• Efficiently transfers heat.

Cons

• It is a bit pricey.

Verdict

The NGK 6619 Iridium IX spark plugs guarantees you improved performance and torque from your engine as they always deliver a proper air to fuel ratio consistently. These spark plugs are ideal for high performance engines.

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Denso 4504 PK20TT Platinum Spark plugs

This spark plug comes with a twin- tip design that consists of an 11mm platinum disc and electrode tip, with an 11 mm titanium ground electrode. The twin- tip design enables the spark plug to complete combustion efficiently which results to a proper air to fuel mixture. As a result, the engine runs smoothly throughout and also improves the gas mileage of the car.

Specs

• Platinum center electrode.
• Twin- tip design.
• Minimum- quench electrode design.
• Gasket seat style.

The purified alumina powder in the spark plug reduces conduction of electric currents and increases heat conductivity which enables the spark plug to perform reliably for a very long time without having to replace them. In addition to this, it also enables the spark plug to work efficiently even in engines that produce a lot of heat due to its impressive dielectric strength. Another feature that makes this spark plug stand out is the copper- glass seal. It basically attaches the insulator and center electrode tightly enabling the spark plug to retain heat throughout which enhances great performance of the engine efficiently.

Pros

• It is resistant to rust.
• It enhances great performance from the engine.
• Improves fuel economy.
• Great heat conductivity.

Cons

• Incorrectly set gap on some spark plugs.

Verdict

The Denso 4504 PK20TT is a good choice of a spark plug if you are looking for an affordable spark plug that will give you an all-round performance efficiently. This is because its features improve the fuel economy, performance of your vehicle and still offers you great durability making it a good pick.

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Bosch ZGR6STE2 Spark Plugs

This spark plug comes with a nickel chromium ground electrode that ensures the engine gets a proper air fuel mixture immediately you turn on the vehicle. Basically the spark plug enables your vehicle to run smoothly right from cold starts and until it attains its preferred engine temperature.

Specs

• Nickel plated shell.
• Nickel – chromium ground electrode.
• Original Equipment design.
• Copper core.

In addition to this, it is equipped with a heavy-duty copper core center electrode which enables high performance engines to operate at their optimal levels throughout even when the engine is being pushed to its limits. It also improves heat transfer of the spark plug which increases the reliability of the spark plug. As a result of this, the Bosch ZGR6STE2 spark plugs have a life span of up to 45,000 miles. Another feature equipped on this spark plug is the nickel-plated shell that prevents the spark plug from corrosion which improves its durability. The plug’s ribbed insulator prevents discharge of sparks between the terminal and metal shell maintaining a reliable air to fuel mixture in your engine consistently.

Pros

• They are very durable.
• Service life of up to 45,000 miles.
• It improves performance of the engine.
• They don’t rust easily.

Cons

• It may not fit other vehicles even when specified for that particular vehicle.

Verdict

This Bosch ZGR6STE2 is a good spark plug for high performance engines such as the BMW N54 engines as it enables the engine to attain optimal performance efficiently. It also has a very long lifespan making it a very good option to consider.

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NGK 4929 standard Spark plug

The NGK 4929 is equipped with a solid copper core which prevents carbon from forming on the firing end of the spark plug. This ensures that the spark plug works efficiently without any form of misfire maintaining good fuel economy throughout.

Specs

• Zinc dipped shell.
• Triple gasket seal.
• Solid coper core.
• Corrugated ribs on insulator.

Its zinc dipped shell prevents rust on the spark plug which enhances long service life before wearing out. Additionally, it comes with corrugated ribs on the insulators which lowers the chances of a flashover in the spark plug. The triple gasket seal prevents the spark plug from leaking which enhances its durability.

Pros

• It is easy to install.
• It does not corrode easily.
• Great overall performance.
• Maintains good gas mileage throughout.

Cons

• Lacks screw- on caps.

Verdict

These spark plugs are suited best for motorbikes. They enable the engine of your bike to run within their optimum temperatures at all times efficiently. Another features that draws us to this spark plug is that it is very easy to install as well.

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Bosch X5DC Copper Spark plug

The Bosch X5DC is a spark plug that comes with an Original equipment design but offers better performance, durability and gas mileage as compared to OEM spark plugs.

Specs

• Nick plated shell.
• Ultra-fine wire.
• Iridium firing pin with laser.
• Copper core.

A continuous laser is welded to the iridium firing pin which covers a maximum angle of 360 degrees which prevents carbon from accumulating on the firing end of the spark plug. This improves the lifespan of the spark plug. It is also equipped with a fine wire and nickel- plated shell that prevents the spark plug from seizing. Aside from this, the Bosch X5DC has a tapered nickel chromium ground electrode that ensures proper air to fuel mixture even on cold starts enabling the engine to run smoothly from the moment you switch on the vehicle. The copper material on the core of the spark plug is also doesn’t corrode easily which enhances durability of the spark plug. One of the best things about these plugs is they are durable and also very reliable. You don’t need any special gap tool for installation.

Pros

• It is very durable.
• It does not corrode easily.
• Enhances efficient cold starts.
• Easy to install and no gapping needed.

Cons

• Poor packaging which may lead to damage on the spark plugs.

Verdict

This spark plug is a good option as well because it actually maintains great performance of your engine by enabling it to run smoothly right from cold start. In addition to this, it also improves gas mileage and has a very long life span.

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NGK BKR7EIX Iridium IX spark plug

NGK’s BKR7EIX spark plug is manufactured to improve the throttle response of your vehicle consistently.

Specs

• Fine wire center electrode.
• Iridium alloy.
• Copper core.
• Trivalent metal plating.

Its iridium alloy works efficiently even when exposed to very high heat. This is due to its high melting point making it an ideal spark plug for high performance engines that constantly produce a lot of heat. It also comes with a fine wire center electrode that produces a stable spark throughout which enhances the durability of the spark plug. The trivalent metal plating prevents carbon from forming up on firing end of the spark plug which reduces the chances of the spark plug getting corroded. This enables the spark plug to maintain good gas mileage and work efficiently for a very long time.. Another feature that comes with the NGK BKR7EIX is the alumina silica ceramic insulator which maintains efficient heat transfer from the spark plug.

Pros

• It has a very long life span.
• Has a high melting point.
• It has superior strength.
• Easy to install.

Cons

• Needs to be gapped in order to fit them properly.

Verdict

These spark plugs are ideal for high performance vehicles because they are able to handle very high temperatures efficiently. So you should consider these spark plugs if you own a turbocharged or supercharged vehicle.

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What to consider when buying spark plugs for your vehicle.

Material

The components used to make a spark plug varies depending on what the spark plug is made for. Therefore, before you purchase them you should look at all the materials used to manufacture the spark plugs and see which fit your intended purpose best. Copper is suited best for vehicles with a low- voltage distributor ignition which is technology used in the older versions. Platinum and iridium on the other hand, are designed to offer great performance efficiently in modern vehicle engines. Platinum spark plugs enhance performance and good fuel efficiency in your vehicle and lasts longer than copper plugs. Lastly, Iridium plugs are the most preferred if your car runs a modern high performance engine as they maintain the performance of the engine reliably while giving you good gas mileage. However, they are pricier as compared to the rest of the spark plugs.

Size

The size of the thread or the nut of a spark plug is also another factor that you should always consider before buying a spark plug for your vehicle. When the thread of the spark plug is not of the correct length as specified by the manufacturer, the piston or valve may strike the plug constantly which leads to serious engine damage. Specific thread lengths come with their specific nut sizes i.e.

Thread length	Nut size
10 mm	16 mm
12 mm	14 mm / 16 mm/ 17.5 mm
14mm	16mm/ 20.63 mm
18mm	20.63 mm

Heat Range

A low heat range spark plug has a long thin insulator nose that heats up faster but doesn’t dissipate to shell readily which is ideal for use on engines that are not too powerful. This is because such engines don’t produce a lot of heat when they are running. A high heat range spark plug on the other hand, has a short tick insulator nose which dissipates heat faster as compared to the low heat range plugs. This is ideal for high performance engines because they normally produce a lot of heat constantly especially when the vehicle is being pushed to the limit frequently. Usually the manufacturer of the vehicle will inform you in the vehicle’s user manual which spark plug is best suited for the vehicle.

Gap style

The gap of the spark plug should be proper in order to hold the duration of the spark long enough for a proper and balanced air- fuel ratio. If the gap is not correct on the spark plugs, this will lead to a poor air- fuel mixture in the combustion chamber which may cause the vehicle to misfire on idle or hesitate when accelerating. A gaper tool and gap gauge are used to adjust and measure the length of the gap respectively.

User- friendliness

Some spark plugs are pre-adjusted and come with the correct sized gap to suit your specific vehicle which enhances convenience as all you have to do is just replace the old plugs with new ones directly at no extra cost.

Conclusion

All these spark plugs are good options for specific motor vehicles and enhance good gas mileage however, it is important to note what spark plugs are recommended for your motor vehicle. For example, Iridium and platinum spark plugs work efficiently on high performance engines because of their ability to handle a lot of heat because of their high melting point. Lastly, Copper spark plugs are the most affordable yet still offer efficiency, good performance and longevity.

FAQs

How do I know my spark plugs are worn out?

When they are worn out your car will lose its overall performance. i.e. rough idling, a drop in gas mileage, hesitation when you accelerate and backfires from your exhaust.

What is the service life of spark plugs?

This depends on the type of spark plug your vehicle runs on. Copper spark plugs usually operate efficiently up to 30,000 miles while iridium and platinum spark plugs last up to 50,000 miles.