The Best 350z Spark Plugs: Recommendation & Specs

Quality spark plugs are vital for getting the most out of your Nissan 350z.

If you have tired spark plugs, your engine might misfire, your car might have trouble starting up, or it could not start altogether.

That miniature bolt of lightning that a spark plug provides has a huge impact on how your car performs.

Bad spark plugs first begin to show signs of wear when you notice uneven idling, a lack of acceleration, and increased fuel consumption. Spark plugs are so cheap, you really have no excuse not to change them out regularly.

A Nissan 350z spark plug change is a straightforward job. If you’ve changed spark plugs on a car from around 1990 onwards, you’ll find it a quick and easy job.

In this guide, we will show you the best 350z spark plugs available today, by type. At the end, you’ll find our overall recommendations for replacing your 350z’s spark plugs.

Nissan 350z Spark Plugs: OEM Specs

Spark plugs are not a one-size-fits-all type of mechanism. For the Nissan 350z, you need plugs with a gap of 0.44 inches, or 1.1mm.

Gapping refers to the distance between the curved conducting electrode and the plug tip where the electricity shoots out from.

Most plugs come pre-gapped, but often copper/nickel spark plugs don’t. For those, you’ll have to use a special “gap tool” to bend the electrode to the right distance.

Different Types of Spark Plugs

There are four main types of spark plugs, named because of the material that makes up the electrode:

  • Copper: These are the most common. They’re the cheapest and wear out the quickest, but give one of the best sparks. They’re good for performance vehicles, but they’re losing popularity. It’s rare to see these in a Nissan 350z nowadays but if you are on a serious budget they will work fine.
  • Platinum: These are twice as expensive as copper plugs, but last twice as long. The spark isn’t as strong though, so they’re better for 350z owners looking for longevity over performance
  • Iridium: These are the most expensive, but they give the best spark, and typically last quite long. Iridium spark plugs are the most commonly used among Z car owners.
  • Silver: These have the best thermal conductivity, but wear out the quickest. They’re mainly used for older models and motorcycles. If someone tries to sell you these for your Z33, run away.

Replacement 350z Copper Spark Plugs

Copper or “standard” spark plugs use nickel-alloy coating for the electrode. The inner core is copper. Copper conducts electricity well, but they have a shorter lifespan than others on the market. Copper plugs are generally lower in cost.

They actually deliver the best spark under the adverse conditions generated by turbochargers or higher compression ratios, so many high-performing vehicles do well using copper plugs (such as forced-induction 350zs).

Champion Copper Plus

Champion Copper Plus Nissan 350z Spark Plug

Manufacturer: Champion
Electrode Type: Copper
Check Prices: Amazon

These are basically the cheapest replacement 350z spark plugs on the market.

Champion’s Copper Plus spark plug uses two patented systems:

  1. the Ultraseal coating which resists corrosion, and
  2. the SAC-9 semiconductor resistor.

These are widely used, common spark plugs, seen in HEMI engines and bigger truck engines, just as often as the 350z. With these plugs you’ll get a nice steady idle, without misfire or bad idling surges.

These plugs spark hotter than any other kind of plug, so even though they may not last long, they’re great for performance. You should also get no hesitation on take off or acceleration.

If your current spark plugs are tired, expect to see a small improvement in your fuel economy with these plugs installed.

Assuming the rest of your car is in good condition, it should feel similar to how it did when it was driven off the showroom floor.

Best Platinum 350z Spark Plugs

Platinum-tipped spark plugs are more expensive than copper because platinum is a rarer element – they cost more to produce.

But platinum spark plugs have great longevity under normal driving conditions. That’s because platinum is harder than copper/nickel, so it doesn’t erode as quickly.

This means the gap at the tip of the spark plug doesn’t widen as the metal wears away, so you shouldn’t see a drop in power, reduced mileage, or intermittent misfires on startup like you would with copper spark plugs.

The lifespan of platinum plugs is typically twice as long as copper ones; anywhere up to 100,000 miles.

Denso Platinum TT

Denso Platinum TT Spark Plug

Manufacturer: Denso
Electrode Type: Platinum
Check Prices: Amazon | FRSport

The first thing you might notice after installing Denso Platinum TT plugs is improved gas mileage. Many Z drivers also claim a slight increase in performance (slightly more horsepower) under normal driving conditions. But that is the result of replacing very worn spark plugs.

It seems that your VQ35DE engine will never ping again with the Platinum TT spark plugs. Even if it’s a high mileage car on low, 87 octane fuel.

Denso is a trustworthy company who makes OEM spark plugs for many Toyota and Honda models, so you can rest assured you’re getting quality with these plugs.

Autolite Platinum

Autolite SL1500 Nissan 350z Spark Plug

Manufacturer: Autolite
Electrode Type: Platinum
Check Prices: Amazon

Autolite’s Platinum spark plugs come with a full platinum tip that ensures you’ll have no gap erosion, which leads to a long life. To maintain that precise gap and increase plug life, they’re Yttrium enhanced. We’ve tried to get our heads around the science, but the summary is that they last longer with Yttrium.

These “double” platinum plugs also use a platinum alloy pad on the ground electrode, providing durability with platinum-to-platinum firing. The nickel-plated shell also helps with corrosion resistance.

Autolite’s plugs are guaranteed for four years. You’ll see better performance, fewer misfires, quicker acceleration, and improved fuel economy with these plugs.

NGK PLFR5A-11 Laser Platinum

NGK PLFR5A-11 Laser Platinum Spark Plugs for Nissan 350z

Manufacturer: NGK
Electrode Type: Platinum
Check Prices: Amazon

NGK Laser Platinum spark plugs are the OEM spark plugs for the 350z, which also means they’re some of the best 350z spark plugs around. They’re proven to last long and perform well.

After installing these plugs, you should notice your 350z starts faster and smoother, is less noisy, accelerates better, and the engine will warm up quicker. Like most others, you’ll also see an improvement in fuel economy.

For installation, it’s worth buying some silver anti seize for applying on the thread of the new plugs. This way it makes it easy to place them on, and will keep the threads and coil boots in good shape. It’ll also make it easy to pull them off when they need replacing.

These spark plugs will reliably do 75,000 miles, but NGK being the high quality brand it is, we’re fairly sure you’ll be able to get away with further.

Iridium Nissan 350z Spark Plugs

Iridium-tipped spark plugs offer better power and more complete combustion, which leads to smoother running engines and a longer lifespan than copper plugs. They are near to the same lifespan as platinum plugs.

Iridium spark plugs are the highest in cost, and typically feature “fine wire” centers that conduct electrical energy well. They are quickly becoming the standard for modern high-tech engines, but they also fare well with older engines like Nissan’s VQ35DE and VQ35HR.

To us, the additional cost is worth it. Where platinum spark plugs have a long life, and copper ones produce a great spark, iridium spark plugs do both.

As a result, most 350z drivers choose to replace their tired spark plugs with iridium ones.

Denso Iridium Long Life

Denso Iridium 350z Spark Plug

Manufacturer: Denso
Electrode Type: Iridium
Check Prices: Amazon | FRSport

True to the product’s name, Denso’s Platinum Long Life plugs will last upwards of 100,000 miles, or close to 8 years!

They’re made with a patented 360-degree laser welding process that ensures a quality bond and structural strength. The large tip on the plug ensures ample power output and great fuel economy.

Your engine will accelerate better and smoother with these spark plugs, and they’re easily better than the OEM plugs. The difference in power and acceleration is like night and day with these plugs installed.

Bosch Double Iridium

Bosch Double Iridium Spark Plug

Manufacturer: Bosch
Electrode Type: Iridium
Check Prices: Amazon

Like the Denso plugs above, the Bosch Double Platinum plugs use a 360-degree laser welding to increase durability and corrosion resistance, providing a 4-times longer service life compared to standard copper plugs. They come with a 7-year performance guarantee.

With these plugs installed, you should see a small improvement in your fuel efficiency and, it’s claimed a 4HP increase. They’re pre-gapped, so installation is easy.

Your engine will be much more responsive and smoother with accelerating with Bosch’s Double Platinum spark plugs installed, and the 7-year guarantee makes them some of the best 350z spark plugs on the market for longevity.

Champion Iridium

Champion Iridium Spark Plug Replacement for a Nissan 350z

Manufacturer: Champion
Electrode Type: Iridium
Check Prices: Amazon

These replacement spark plugs are not made for high performance gains, but rather for longevity. The fine-wire iridium center and platinum grounding help give them maximum life.

You’ll see a faster throttle and better response with these plugs installed. The V-trimmed ground electrode gives the plug a sharper spark focus, which will increase your power a bit (and that’s also what gives you the better throttle response).

Champion’s Iridium plugs aren’t compatible with many models, but they are with the Nissan 350z of all years, and they’re a good replacement plug.

Nitrode SP-NP21

Nitrode SP-NP21 Nissan 350z Spark Plug

Manufacturer: Nitrode
Electrode Type: Iridium
Check Prices: Amazon

Nitrode claims their SP-NP21 platinum spark plug delivers the most powerful spark ever, and that it’ll give your car a clean combustion and increased horsepower.

What we can say is that the Nitrode plug will make your engine run smoother, all the way through the power band, up to 7,000 RPM. The engine will idle smoother, too. For those in cold climates, your 350z will definitely start easier with these plugs installed (especially if you combine them with a replacement battery as well).

You should see a nice little boost in your low and high-end power. It’s crazy, but your ride might really seem like a whole new car with just this cheap, tiny replacement.

Our Favorite 350z Spark Plugs

Below you’ll find our Nissan 350z spark plug recommendations, depending on your needs.

Cheap 350z Spark Plugs: Champion Copper Plus
Sometimes the best solution is a cheap one. Though copper spark plugs are fairly old technology by today’s standards, they are still a great spark plug in comparison to the worn ones that are probably in your car right now.

High Performance 350z Spark Plugs: Bosch Double Iridium
If you’re looking to get an improvement MPG and your car’s performance, you can’t go wrong with the Bosch Double Iridium spark plugs. Most cars see a small improvement in fuel efficiency and a small bump in horsepower. They also have a 7-year guarantee, which is hard to beat.

Long-Lasting Replacement Spark Plugs: Denso Iridium Long Life
If you want spark plugs that will last a long time, possibly longer than you keep your car itself, our recommendation has to be these Denso units. They’ll last upwards of 100,000 miles, or 8 years (though we’d probably only keep them for around 75,000 miles at most).

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