Compare Spark Plug Replacement Deals

If a garage has just told you your car needs new spark plugs, the good news is that this is one of the most routine jobs a petrol engine can need, and comparing your options for it doesn't have to be complicated.

Enter your reg and postcode below to see instant, side-by-side prices from local garages for your exact car, rather than a single averaged national figure that may bear no relation to what your job actually costs.

Why Book Your Spark Plug Replacement with BookMyGarage?

• BMG-Verified Garages Across the UK. Local businesses that offer great value and consistently meet service standards. Look for the BMG-Verified badge to find the garages we’ve ensured meet our high standards for customer service, ratings, and reliability. 

• We Show the Full Picture. All up front: prices, reviews, availability, and distance, so you can choose the right garage based on what matters most to you.

• Real Reviews. Genuine, verified feedback from drivers like you. Every review helps you book with confidence.

• No Upfront Payment. We won’t ask for payment details when you book. Pay the garage directly once the work’s complete*.

• Compare & Book in Seconds. See your options side by side and choose the right garage for you. No jargon. No stress. No surprises.

• Support Local Garages. We connect drivers with quality local businesses that keep communities moving.

 *some mobile technicians (that come out to you) may require an upfront payment or commitment, please check this with them first.

These are just some of the reasons to choose BookMyGarage - enter your reg and postcode to see how we can help you make a confident, informed choice when booking your spark plug replacement now.

Signs You Need a Spark Plug Replacement

Worn spark plugs rarely fail without warning first, so it's worth knowing what to look and listen for before the problem gets worse or more expensive to put right.

●      Difficulty starting or the engine stalling, especially in colder or damper weather

●      A rough or uneven idle, where the engine shakes or judders while you're stationary

●      Misfires, felt as a hesitation, jolt or momentary loss of power while driving

●      Reduced fuel economy, as worn plugs make the engine work harder to burn fuel efficiently

●      Poor acceleration, where the car feels sluggish or slow to respond when you put your foot down

●      An illuminated engine management light, which can point to spark plugs among a number of possible causes

None of these symptoms need to mean anything serious on their own, but a misfire or a rough idle can have more than one underlying cause, so it isn't always obvious from how the car feels that spark plugs are to blame. If your engine management light comes on, a full diagnostic check can confirm exactly what's triggering it before you commit to any repair, so you only pay for the job your car genuinely needs.

What Do Spark Plugs Do?

Every petrol engine relies on spark plugs to run at all. Each one sits at the top of a cylinder and fires a small spark at exactly the right moment to ignite the mixture of fuel and air inside, and that tiny explosion is what actually powers your engine. A three-cylinder city car might have three plugs doing this job, while a larger six or eight-cylinder engine has more, each firing in careful sequence thousands of times a minute.

Over time, the metal tip of each plug wears down and the gap it fires across widens, so the spark becomes weaker and less reliable, and it's this gradual wear that eventually causes the symptoms above.

It’s worth noting that spark plugs are only present in petrol engines. If you drive a diesel car, they use glow plugs instead, so you’ll need to get those replaced if you notice an issue.

How Often Should You Change Your Spark Plugs?

How long your spark plugs last comes down mostly to which type your engine uses, rather than one single mileage figure that applies to every car. Standard copper plugs are the shortest-lived, typically needing replacement every 20,000 to 30,000 miles, while platinum or iridium plugs (most commonly found in newer cars) are built to last considerably longer, often anywhere from 60,000 to 100,000 miles or more.

Check your vehicle handbook to find the manufacturer recommended interval for your car.

What Affects the Cost of a Spark Plug Replacement?

Spark plug replacement is one of those jobs where a single "average price" genuinely doesn't tell you very much, because the biggest cost factor is how many spark plugs your engine actually has, and this varies from car to car.

A small three-cylinder engine needs far fewer plugs, and less labour to reach them, than a larger six or eight-cylinder engine.

Plug type matters too. Copper plugs are the cheapest to buy, while platinum and iridium plugs cost more upfront but last considerably longer, so the total cost depends partly on which type your car takes and which your garage recommends. Labour time is the last piece of the puzzle, and it varies by how accessible the plugs are on your particular engine. Some sit right on top and take minutes to reach, while others are buried behind other components and take a good deal longer to get to.

Rather than quote one figure that might not reflect any of this, the most accurate way to know what your job will cost is to compare real, instant prices from local garages, based on your actual reg.

Every garage on our comparison site sets their own prices themselves, so the price you see is the price you’ll pay (unless you agree to additional work with them directly). Enter your reg and postcode to see how much a spark plug replacement costs near you and book in seconds, with verified reviews available to help you find the best deal for your needs.