Table of content
25 February 2025 Spark plug replacement: cost, signs, and symptoms
Finding the right spark plugs for your car doesn't have to be a guessing game. Your engine's performance, fuel efficiency, and longevity all depend on choosing the right type. The best way to ensure a perfect match? Check your owner's manual or use an online parts finder.
Fitting the wrong spark plugs can lead to misfiring, poor mileage, and even engine damage, so it's worth getting it right. Not sure where to start? A mechanic or car parts expert can help you make the best choice. Regular replacement will keep your engine running smoothly and save you money at the pump.
Spark plug replacement cost
On average, you'll pay around £85, although prices typically range from £55 to £125. The final price will depend on factors such as the number of spark plugs your engine requires and the type – copper, platinum or iridium – each of which has a different lifespan and price. Labour costs also vary, with some vehicles requiring more time-consuming replacements. Do-it-yourself installation can save money, but it's important to make sure you have the right type of spark plug and that it's installed correctly.
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Spark plug average change cost by location
The cost of replacing spark plugs varies across the UK, influenced by factors such as regional labour rates and demand. For example, in major cities such as London, average hourly labour rates range from £50 to £100, while in areas of lower demand, rates can be as low as £35 to £50. In addition, the type of mechanic – such as a mobile mechanic versus a dealership technician – can affect the overall cost.
Below is a table outlining the average spark plug replacement costs in various UK cities:
|
UK Location |
The average cost in (£) |
|
Birmingham |
£98 |
|
Bristol |
£135 |
|
Glasgow |
£97 |
|
Leeds |
£85 |
|
Liverpool |
£96 |
|
London |
£109 |
|
Manchester |
£100 |
|
Newcastle |
£113 |
|
Sheffield |
£83 |
-25%
Article number: 1496
compared to
RRP
£ 23,65
£ 17,70
Price per item
price incl. 20% VAT, excl. delivery costs
-58%
Article number: Z332
compared to
RRP
£ 24,01
£ 9,91
Price per item
price incl. 20% VAT, excl. delivery costs
-17%
Article number: 90911
compared to
RRP
£ 14,79
£ 12,27
Price per item
price incl. 20% VAT, excl. delivery costs
-15%
Article number: 97098
compared to
RRP
£ 15,54
£ 13,09
Price per item
price incl. 20% VAT, excl. delivery costs
-26%
NGK Spark plug
M14 x 1,25, Spanner Size: 16 mm
Article number: 91898
compared to
RRP
£ 19,16
£ 14,09
Price per item
price incl. 20% VAT, excl. delivery costs
Spark plug average change cost by car brand
The cost of replacing spark plugs can vary significantly depending on the make of the car, engine complexity, and labour rates. Below is a table of average spark plug replacement costs for different car brands, including parts and labour. Keep in mind that high-performance or luxury vehicles may require more expensive plugs and additional labour. Prices can also vary depending on location and service provider. Use this as a general guide to estimate your likely costs.
|
Car Brand |
The average cost in (£) |
|
Mercedes-Benz |
£31–£246 |
|
Audi |
£15–£72 |
|
BMW |
£27–£257 |
|
VW |
£31–£92 |
|
Ford |
£50–£300 |
|
Peugeot |
£33–£91 |
|
Nissan |
£22–£134 |
|
Toyota |
£21–£183 |
|
Renault |
£18–£123 |
|
Vauxhall |
£55–£125 |
|
Honda |
£30–£124 |
How often to change spark plugs
Most vehicles need a replacement every 30,000 to 90,000 miles, depending on the type of spark plug and manufacturer recommendations. Ignoring worn-out plugs can lead to several warning signs, including rough idling, poor acceleration, misfires, trouble starting, and decreased fuel efficiency.
If you notice these symptoms, it's time to check your spark plugs. Copper plugs wear out faster, while platinum and iridium options last longer. Regular replacement ensures smooth engine performance, better fuel economy, and reduced emissions. If you're unsure, consult your owner’s manual or have a mechanic inspect them.
Do I need to replace all spark plugs at the same time?
It's always a good idea to change all your spark plugs at the same time – one for each cylinder in your engine. Why? Because mixing old and new plugs can lead to uneven performance, misfiring or rough idling. Because spark plugs wear at a similar rate, replacing them all at once ensures smooth engine operation, better fuel economy and fewer trips to the garage. Replacing them together can also save on labour costs in the long run. If one spark plug fails, chances are the others won't be far behind.
How long does it take to change the plugs?
Changing spark plugs on a four-cylinder engine usually takes about an hour, while V6 and V8 engines may take longer. The exact time will depend on factors such as engine design and accessibility – some vehicles require the removal of components to reach the plugs, adding extra time. If you're an experienced car mechanic, a DIY replacement can be straightforward with the right car tools. However, for complex engines or hard-to-reach plugs, a mechanic may be the best choice.
-51%
Article number: Z90
compared to
RRP
£ 12,91
£ 6,24
Price per item
price incl. 20% VAT, excl. delivery costs
-48%
DENSO Spark plug
M12x1.25,
Article number: VXUH20I
compared to
RRP
£ 31,83
£ 16,28
Price per item
price incl. 20% VAT, excl. delivery costs
BOSCH Spark plug
M 12 x 1,25, Spanner Size: 14
Article number: 0 242 129 510
£ 5,26
Price per item
price incl. 20% VAT, excl. delivery costs
BOSCH Spark plug
M 12 x 1,25, Spanner Size: 14
Article number: 0 242 140 565
£ 15,04
Price per item
price incl. 20% VAT, excl. delivery costs
-36%
NGK Spark plug
M14 x 1,25, Spanner Size: 16 mm
Article number: 94167
compared to
RRP
£ 33,67
£ 21,26
Price per item
price incl. 20% VAT, excl. delivery costs
Which plugs will be suitable for my car?
The right spark plugs for your car depend on its make, model, engine type, and year. To find the exact match, check your owner's manual or use an online parts finder from a reliable brand.
Spark plug types vary:
- Copper – best conductivity, but wears out quickly (good for older cars).
- Platinum – longer life and better efficiency than copper.
- Iridium – most durable, improves fuel efficiency and is ideal for modern engines.
Always use the correct heat range and gap size specified by your manufacturer. Incorrect plugs can cause misfiring, rough idling or poor fuel economy. If in doubt, consult a mechanic or auto parts store.
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New spark plugs cost
You can buy most spark plugs for about £80, but you can spend up to £130 depending on the type and brand. Copper plugs are the cheapest but wear out faster, while platinum and iridium plugs last longer and offer better performance. High-performance or specialist spark plugs for luxury and sports cars tend to be more expensive. The total cost also depends on whether you're buying a single spark plug or a complete set.
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