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Do New Cars Have Spark Plugs?

Do New Cars Have Spark Plugs?

Spark plugs can be finicky, and they seem a little bit outdated considering all of the modern bells and whistles you find on vehicles these days.

With all of the advancements in technology, you may find yourself wondering if cars still use spark plugs.

Cars still use spark plugs as they are responsible for igniting fuel in the combustion chamber. Most vehicles have a single spark plug for each cylinder in the engine, however, some use two spark plugs per cylinder.

Keep reading to learn more about how spark plugs are used in cars!

Do Modern Vehicles Have Spark Plugs?

Nearly every car and motorcycle on the road has a set of spark plugs, sitting beneath its hood. You have to use them if you’re driving something that has an internal combustion engine. 

Internal combustion engines ignite fuel to create explosions. This happens inside of a combustion chamber, where a piston harnesses the power. 

This explosion occurs after the fuel gets lit by a spark plug. 

A broken spark plug won’t ignite the fuel-air mixture, causing your engine to misfire. You may still be able to drive the car, but it won’t drive well. 

Most spark plugs last for at least 60,000 miles. Some of them have been designed to last the entire life of your engine, though. 

You’ll probably want to replace them if you’ve had the car for more than 10 years. 

You should also check out the car’s ignition cables while you’re replacing them, too. They often wear out after you’ve had a car for that long. 

Do Fuel Injected Cars Have Spark Plugs?

Fuel injected cars do have spark plugs, but these vehicles don’t put spark plugs under the same demands as fuel-injected ones.

There isn’t as much space in the combustion chamber of a fuel-injected engine. 

That means there’s not as much space between the spark plug and cylinder head. In fact, most fuel-injected engines submerge their spark plug’s electrode in fuel. 

Placing the spark plug’s central electrode there improves the engine’s reliability. 

Fuel is sprayed into the chamber at the last moment, when it rapidly mixes with the air. 

If you have a fuel-injected engine, you’ll need to use specific parts. Your sparks plugs have to sit in exactly the right spot to do their job properly. So, you should always check your manual to see which spark plugs to use. 

Do Automatic Cars Have Spark Plugs?

An automatic transmission usually has the same number of spark plugs and pistons. You’ll have one of them for every piston the engine has. 

Most of the time, your spark plugs should last for at least 30,000 miles. You can buy some that are made with gold or platinum if you’d like them to last longer. 

Replacing the spark plugs is not too difficult, especially compared to other projects. 

Just make sure not to overtighten the new ones when you’re putting them in. Otherwise, you could damage them before ever getting a chance to use them. 

We’d recommend grabbing a gapping gauge. These let you measure the size of your spark plug’s gap. 

You can insert it by pushing it between the center and ground electrodes. It should feel like it’s snug once you’ve put it between them. 

If it doesn’t fit between them, you’ll need to adjust the spark plug.

We’d also suggest working on one spark plug at a time if you’re replacing them by yourself. It’s a lot easier to keep track of all the wires if you’re only messing with them one at a time. 

Do Diesels Use Spark Plugs?

Diesel engines use air compression to heat up their combustion chambers. So, they don’t need spark plugs to work properly. 

Cranking a diesel still requires some help, though. They use a device called a glow plug, instead. 

Internal combustion engines use them to ignite fuel every time the pistons go around. Diesel engines only use a spark to ignite the fuel when they’re first starting. 

After they’ve cranked up, they use compression to ignite the fuel. 

So, glow plugs only turn on when you’re cranking a diesel engine. After that, they’re not doing anything at all. 

They’re actually a type of heating element. When you turn on the engine, it sends electrical current coursing through the glow plugs. 

This causes them to heat up, and they get really hot. 

Fuel injects into the combustion chamber while the glow plugs warm up. It mixes with air as it’s entering the chamber, and then it ignites. 

That’s how glow plugs help your diesel crank reliably, even in the cold. 

Designed for cold weather, high-nitro glow plugs work well when it’s frigid outside. Pay attention to the nitro percentage when you’re shopping for glow plugs. This can tell you how hot they’ll run when you’re using them. 

Large engines usually need glow plugs that run colder. So, you may need to get some that are high-nitro. 

You can figure out which ones to use in your engine by taking a look at your manual. It should list all the ones that are compatible in there. 

Do Electric Cars Have Spark Plugs?

If you have an electric car, then you won’t need to buy spark plugs. They don’t use them to power their engines because they’re all-electric. 

Spark plugs are part of internal combustion engines. That’s because they need an ignition source. 

Electric cars don’t generate power by using combustion, so they don’t need them. 

Pressing down on its accelerator tells its engine to deliver more power to its wheels. This all happens without any combustion at all. 

Hybrid cars still need spark plugs, though. They use some electricity when you’re driving them. But, they still have combustion engines, too. So, you’ve still got to replace their spark plugs once in a while. 

How Many Spark Plugs Does a Gas Engine Have?

Replacing your engine’s spark plugs can prevent it from misfiring while you’re on the road. If you’ve had any misfires lately, it might be time to get new plugs. 

You can figure out how many your car has by looking in its manual. Most of the time, you’ll need to get one of them for each piston. You should still double-check before getting anything, though. 

Some cars use two spark plugs for each of their pistons. 

Always replace all your spark plugs at the same time to make sure your engine works well. 

Replacing a few of them might cause the other cylinders to wear out faster. They won’t ignite as efficiently because they’d still be using old equipment. 

Work on your spark plugs one by one if you’re replacing them by hand. You want to disconnect their ignition wires one at a time, so you don’t confuse them. Finish replacing one completely before you move on to the next one. 

Buy enough new plugs to replace all the old ones, too. Don’t try to get everything done if you’re in a rush, either. 

Putting new ones in can take a bit if you’ve never done it before. 

You can safely assume you’ll need at least as many plugs as your engine has pistons. 

So, if you have a 4-cylinder engine, you’ll need at least 4 plugs. You might need up to 8 of them, though, depending on your engine’s design. 

Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!