The Best Spark Plugs for 5.3 Silverado: How to Find the Best One

The Best Spark Plugs for 5.3 Silverado: How to Find the Best One

If you need to find new spark plugs for your 5.3 Silverado, you’ve come to the right place! A Silverado is a powerful vehicle, which requires tough parts. A spark plug, although small, is a vital piece of your vehicle’s equipment – and without decent spark plugs, it will not run as efficiently as it could.

If your vehicle doesn’t always start reliably, is starting to suffer from rough idle, or is just not giving you the performance you think it should, then the sparkplugs might well be the culprit.

It could be that you can’t even remember the last time your spark plugs were changed. You may be surprised at the difference a new set of spark plugs can make. Today, in our guide on how to find the best spark plugs for 5.3 Silverado, we’ll explain why they’re so important, and give you an overview of the best spark plugs to suit your vehicle.

First, let’s explore what a spark plug actually is, and how it works.

What is a Spark Plug?

spark plug

Have you ever had a car that doesn’t always reliably start? Maybe it starts nine out of ten times, but you know that tenth time isn’t going to work? It could well be a busted or worn sparkplug that’s causing you problems.

Spark Plugs are a tiny part of your car that allows it to start. When you start up the car, a tiny spark of electricity crosses a small gap, which starts the ignition for the combustion, which starts up the engine. All of this happens in mere milliseconds – but it makes the difference between your car starting up, or not staring at all.

A spark plug also has another function – it transfers heat away from the combustion chamber. This is a very important job. The phrase ‘thermal performance’ is used to describe how the spark plug dissipates heat, and how well it holds its temperature.

Spark Plugs are made of the following parts:

  • Insulator – this is molded from aluminum oxide ceramic. It should produce high thermal conductivity.
  • Ribs – These grooves in the side of the insulator should help improve the grip of the spark plug boot to the plug body – some more expensive models have this, to help improve shock resistance and keep the spark plugs lasting longer. Some of the models we mention later in this article have ribs for this purpose.
  • Shell – this is usually steel-plated to keep it lasting longer.
  • Hex – this allows you to install or remove the spark plug.
  • Nose – in the gap area, this has to be resistant to deposits from carbon, fuel, and oil. It’s important that the gap area is kept clean so that it continues to perform properly.
  • Ground electrode – this is normally made from nickel alloy steel.
  • Center electrode – these are also made from thermal material, but this can vary (as we will explore shortly).
  • Gap – this refers to the precise distance between electrodes. This is the gap that the spark has to jump across to kickstart the engine.

Spark Plugs vary in thread size and heat range. It’s always important to check that the model you’re looking at will fit in your vehicle before you invest in it. Most cars have four cylinders and therefore require four spark plugs. (Unless it’s a diesel car – these use something known as ‘glow plugs’ instead).

Spark Plugs come in four categories

spark plug types


Copper spark plugs are made with a solid copper core, with the center electrode made from nickel alloy. Because the materials used in copper spark plugs are softer, they’ll need changing more often – around every 20,000 miles. They’re normally found in older vehicles.

Single Platinum

Single platinum spark plugs have a platinum disc welded to the tip of the center electrode. They’re tougher than copper spark plugs, lasting up to 100,000 miles. They’re good at preventing deposit build-up, but the downside is they tend to be more expensive.

Double Platinum

Double platinum spark plugs, as the name suggests, have double the amount of platinum plating (on the center electrode and the ground electrode). This makes them more efficient, but also makes them pricier. They do tend to last a long time.


These are the most expensive, but they’re considered to be the best. They are powerful, and though –they have a great lifespan of up to 25% longer than platinum spark plugs. These are the most expensive spark plugs, but due to their toughness and longevity, many people find them to be worth the investment.

How Do You Know When Your Spark Plugs Need Replacing?

So how can you tell when your spark plug needs to be changed? You may notice a few of the following symptoms:

  • Your car may not be able to sustain maximum power
  • You may notice a drop in fuel economy
  • Your car may not start reliably every time
  • Your car may completely fail to start
  • You may notice a strange rattling/knocking sound (this is the pistons making a noise when the combustion fails)

Spark Plugs wear down for a variety of reasons, but they all fail eventually. Some are stronger than others and will, therefore, last longer. It’s important to keep your sparkplug working properly, however – it can make a difference to how well your car runs and could help reduce harmful emissions.

When you come to change your spark plug (or when checking your car – it’s a good idea to get into the practice of good car maintenance), you may notice it looks different than it used to. Here’s a quick rundown on what it may look like if it is failing:

  • Burned – if it looks burned or melted, the spark plug could be running too hot, or the engine could be overheating.
  • Oily – black oil deposits could suggest oil is leaking into the cylinders. This is a problem that will need to be checked by a professional.
  • Sooty – you may notice a deposit of soot on the electrodes or insulator tip. This is carbon-fouling, and can be caused by driving at low speeds, a dirty air filter, or rich fuel.
  • Wet – if you try to start up the engine too many times without firing it up, the engine can flood. The spark plug might become wet in this case.
  • Broken – if the electrodes are broken, you may have the wrong spark plugs installed.
  • Worn – this will happen to all spark plugs eventually. If your spark plug is looking a bit worn or tatty, you’ll have to consider buying a new one.

Spark Plugs sometimes come ‘pre-gapped’, which means that the gap that the spark has to travel has been precisely measured. Sometimes this gap can increase over time, which will prevent your car from starting up reliably. It’s best to check, even with pre-gapped spark plugs, if the gap is actually the right size – you can do this by using a tool that measures it.

Should I Buy a New Sparkplug, or Try to Replace It?

spark plugs

This is a good question. You may be able to get a little more life out of your spark plug. You can easily clean off a build-up of soot, for example, using a piece of very fine sandpaper, and then blowing out the debris from the grooves using a blast of air. You can also buy spray-on plug cleaner.

However, as spark plugs are fairly inexpensive, you may decide it’s worth just changing the spark plugs for new ones. It’s a good idea to keep a note of when you change them, so you can roughly work out when they’ll need to be changed again.

How do I Install a Spark Plug?

Generally speaking, the process is as follows:

  • Clean out the spark plug hole
  • Give the threads of the spark plug a light coating of oil from the dipstick (but be careful not to let it drip onto the electrodes)
  • Thread the plug into the engine, turning clockwise
  • Turn it at least twice before using the socket and ratchet
  • Put the spark plug socket over the spark plug, and keep turning it until it fits snugly

You can then check the wires while you’re there, in case they need replacing at the same time. If you need to see this for yourself, then there are plenty of videos online that break it down step-by-step. Alternatively, you could consider having it professionally fitted by a mechanic, which will save you time but cost you money.

What to Look for When Buying a Spark Plug

Here’s what you need to consider when you’re buying a new spark plug:


You’ll need to make sure that your spark plug is compatible with your vehicle. Amazon have a built-in toolbar that allows you to check if your vehicle is compatible with the parts you’re looking at, which is helpful. If not, check the owner’s manual – it should explain which type you need.


You may think that it’s a good idea to go for a copper spark plug because they’re the cheapest and will therefore save money. However, you can’t downgrade when it comes to spark plugs – sometimes you can go up a level to a more expensive type, but generally, trying to buy a spark plug made from softer material is not a good idea. Again, your owner’s manual should explain this.

Price Point

Price is usually something you want to consider when buying car parts. With sparkplugs, the difference in price is usually negligible, but you may decide to stick with the lowest level you can go with as opposed to buying the most expensive one available to you.

Age of Vehicle

Pre-1980’s vehicles are more likely to use copper spark plugs. You’ll want to make sure the age of your car is appropriate for the spark plug you want to buy.

Best Spark Plugs for 5.3 Silverado – an Overview

So, you’ve got a 5.3 Silverado. What are your options when it comes to spark plugs?

The 5.3 Silverado is a powerful vehicle, which requires tough parts that will be up to a lot of wear and tear. For that reason, iridium is best suited to the Silverado. All the models we’ll be looking at today will be made from iridium. Although they’re all quite similar, there are a few differences between them, so it’s worth looking at each one to figure out which one is best for you. We’ll look at their features and pros and cons to help you decide.

ACDelco 41-100 Professional Iridium Spark Plug


acdeco 41-110

You’ll find many vehicles fitted with these sparkplugs – they’re a great choice. Thanks to the iridium, they’re very strong, and they have a very high melting point, meaning they’ll last longer. The iridium fine-wire electrode burns away carbon deposits on the tip of the plug as they form, meaning you won’t have to worry about carbon deposits building up.

The one-piece suppressor seal blocks radio frequencies that can impact the electronics in vehicles, too. Plus, it has suppressor seal meters – this helps to make the electrodes last longer and helps to prevent combustion leakage.

The gap will last for a long time in these spark plugs, so you don’t have to worry about gap widening. It helps enable quick acceleration. The electrodes last longer than cheaper spark plugs. On top of that, you’ll get a 12-month or 12000-mile limited warranty (whichever comes first) – so you know you’ll be covered if they fail before the year is up.

Reviewers say they’ve noticed an improvement in fuel economy and smooth startups since installing these spark plugs, which is a great endorsement.

Pros of ACDelco 41-100

  • Very strong
  • Long-lasting
  • Comes with a 12-month warranty

Cons of ACDelco 41-100

  • There are fakes of these floating around on Amazon, so you need to be careful when buying
  • May not be properly gapped – it’s best to check this first

NGK-90813 Laser Iridium Sparkplug

ngk 90813

This is another solid choice if you want to go for iridium. It has a laser-welded iridium center electrode tip, trivalent metal plating, and a platinum disc welded to the backside of the ground electrode – this makes it durable and long-lasting. It has a longer insulator nose, which helps to prevent fouling. Corrugated ribs on the insulator prevent flashover. It also has a triple gasket seal to eliminate combustion gas leakage.

These spark plugs will provide better fuel economy and will reduce your emissions, too. Basically, you can’t really go wrong with these. The high performance does correlate to a higher price point. However, they should last you a long time – so you may decide the initial investment is worth it.

Pros of NGK-90813 Laser Iridium Spark Plug

  • Very tough and durable
  • Designed to prevent fouling, flashover, and gas leakage
  • Improves fuel economy
  • Reduces emissions

Cons of NGK-90813 Laser Iridium Spark Plug

  • Higher price point

BOSCH 9602 Double Iridium Spark Plug

bosh double iridium

Another good iridium choice, these spark plugs come with a double iridium firing pin and ground electrode inlay. This gives 4x longer service life, compared to copper spark plugs. It has a 0.6mm fine wire firing pin, which provides great ignitability, and helps it to perform well. It’s designed to be durable, with 360-degree continuous laser weld fuses, in order to resist corrosion. It comes pre-gapped, too.

The best part? It comes with a 7-year performance satisfaction guarantee. So, if something goes wrong, you know you’re covered for a while to come. Reviewers found they work incredibly well for certain vehicles, and that they last for a long time, improving their car’s performance. They did say that they can be a bit fiddly to install, however.

Pros of BOSCH 9602 Double Iridium Spark Plug

  • Great service life
  • Durable
  • Corrosion-resistant
  • 7-year performance satisfaction guarantee

Cons of BOSCH 9602 Double Iridium Spark Plug

  • Doesn’t work as well in all vehicles
  • Can be a little difficult to install

ACDelco 41-103 Professional Iridium Spark Plug


acdelco 41-103

Just like the 41-100, iridium offers great engine idle stability, and smooth performance. It has small, efficient electrode designs – this will give you a reliable start and quick acceleration. The electrode will burn away carbon deposits on the tip of the plug even as they form. Like previous models, it has a suppressor seal to help block radio frequencies that impact vehicle electronics. ACDelco are a great company to buy from, as they have a century’s worth of technical knowledge and experience.

Pros of ACDelco 41-103 Professional Iridium Spark Plug

  • Suppressor seal blocks radio frequencies that can impact vehicle electronics
  • Gives a smooth performance
  • Burns away carbon deposits as they form
  • Lasts for a long time

Cons of ACDelco 41-103 Professional Iridium Spark Plug

  • Can sometimes arrive damaged – so need to make sure they’re all in working order when they arrive

NGK TR5IX Iridium IX Sparkplug

ngk 7397

Considered to be one of the best iridium spark plugs that NGK offers, the Iridium IX offers great ignitability, good throttle response, and brilliant anti-fouling. The laser welded fine iridium tip is long-lasting and gives a consistently stable spark. The long insulator nose helps to prevent fouling, and the corrugated ribs prevent flashover.

You’re also less likely to get combustion gas leakage when using these, due to the triple gasket seal. It’s durable when it comes to heat and electrical wear. It also has trivalent metal plating – this is great for anti-corrosion purposes. Users praise the Iridium IX for its superior quality. Reviewers also suggest they are very easy to switch in and out, and that the difference in performance between previous sparkplugs and the IX is huge.

Pros of NGK TR51X Iridium IX Sparkplug

  • Gives great ignitability and good throttle response
  • Long insulator nose prevents fouling
  • Corrugated ribs prevent flashover
  • Durable and long-lasting

Cons of NGK TR51X Iridium IX Sparkplug

  • Like previous spark plugs, there are a lot of fakes floating around on the internet, so you have to be careful which one you choose.


Is a pre-gapped spark plug accurate?

Not necessarily. Although many manufacturers claim that their spark plugs are pre-gapped to perfection, sometimes they can arrive a little bit off. The gap between electrodes must be exactly right, otherwise, it won’t fire efficiently. So, it may be worth gapping your spark plug yourself when they arrive. You can do this using a tool, like a feeler gauge. It may take a little longer, but it’s worth doing to make sure your engine fires up reliably every time.

Do spark plugs increase performance, and if so, how?

Yes, spark plugs can have a real difference in the performance of your car. It will help your vehicle to work more efficiently, improve your fuel economy (hopefully saving you money in the long run), and it will even reduce your exhaust emissions.

How does a spark plug impact emissions?

Worn sparkplugs (and spark plug wires) can impact your emissions, giving you a worse score if you had an emissions test – this is because an old spark plug can increase your hydrocarbon and carbon monoxide emissions. Buying new, good-quality spark plugs and ensuring they are gapped to the exact right distance can help your car to run more smoothly and efficiently.

My check engine light has come on – could it be the spark plug causing it?

Well, a check engine light suddenly coming on could be caused by a lot of different things – but yes, a failing spark plug could be one of those things. It’s always worth giving them a quick check, especially if you can’t remember when they were last changed.

What is rough idle?

Rough idle is the term for the strange, jittery sound your vehicle may make while it is idling. A good spark plug will give you smooth idling, i.e., no odd noises. So, if you notice strange noises happening, your spark plugs could be the culprit.

What is a spark plug socket?

Spark Plug sockets are optional, but they are used to fit spark plugs into engines. They help the spark plug to sit snugly in the right place, and also give it some protection from being bashed around as you drive. However, some people don’t use them at all. You may want to use them to help the installation process run a bit more smoothly.

I want to change my spark plug – what tools do I need?

You will need a ratchet, a gap gauge, and a torque wrench. You may also want to use a sparkplug socket.

How long should it take to change my spark plugs?

It takes around an hour to change four spark plugs. So, it depends on how many cylinders you have in your engine.

Should I have my spark plugs changed professionally?

That depends on how comfortable you feel doing it yourself. If you’d rather know your sparkplugs are definitely installed properly, or you don’t have the time to do it yourself, you could get a professional to do it for you – but it will cost you around $100-150.

What are spark plug wires?

Spark Plug wires, or emission wires, transfer the spark from the coil to the plugs. Emission wires can become brittle, or even snap completely. If you’re changing your spark plugs, it’s probably worth checking out the condition of the wires, too.

Does a spark plug run from the battery?

Yes. An electrical current travels from the battery to the induction coil, which gives enough voltage to ignite the plugs.


We hope this article has helped you! If you think they could do with a change, any of the sparkplugs we listed here could work well for you. If in doubt, however, always check if your vehicle is compatible by looking at the owner’s manual.

A decent set of new spark plugs could make a world of difference to your driving experience, improving fuel performance and lowering your emissions – so you’ve got nothing to lose by investing in some good ones. You might be surprised at how well new spark plugs could work for you.

Did you enjoy this article? You might like our A-Z Guide to Upgrade Your Car Audio, or our guide to the Best Types of Brake Pads for Your Car.

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David Borgogni

David has been working with cars for over 10 years and is a freelance writer who specializes in automotive technology. He covers the topics that matter most to the consumer. Anything new in the automotive industry? David will likely be able to tell you about it.