NGK PMR8A Platinum Spark Plug (5851)
Original price was: £37.40.£20.81Current price is: £20.81.
NGK PMR8A Spark Plug – Stock No. 5851
The NGK PMR8A is a high-quality replacement spark plug designed for reliable ignition and consistent performance. It helps your engine start cleanly, idle smoothly, and deliver stable power under everyday driving and spirited use.
NGK’s precise heat range control (8 on NGK’s scale) helps manage combustion temperatures, reducing the chance of knock and pre-ignition under load. A built-in resistor cuts electrical noise that can affect radios and sensitive electronics.
If you are tuning or upgrading, choose the correct heat range for your engine. Too hot can cause knock. Too cold can foul. Use the site’s vehicle lookup to confirm fitment, or check the Vehicle Fitment tab for full details.
| Part Number | PMR8A |
| NGK Stock Number | 5851 |
| GTIN | 087295158517 |
| Category | 686 – Spark Plug |
| Heat Range (NGK scale) | 8 |
| Resistor | Yes |
| Spark Gap | Factory set – adjust only to manufacturer spec |
| Electrode Style | Fine-wire centre electrode with ground strap |
| Thread/Reach/Hex | As per OE specification for listed applications |
| Seat Type | As per OE specification for listed applications |
- Built to OE standards for consistent spark and long service life.
- Stable idle and improved cold starts compared to worn plugs.
- Resists fouling under stop-start and short-trip use when correctly specified.
Tip: Always torque to the vehicle manufacturer’s spec and check gap against OE data.
The price displayed is for a single plug, please add the desired amount to your basket.
| Weight | 0.05 kg |
|---|---|
| Dimensions | 10 × 3 × 3 cm |
| Brand |
NGK-5851 Confirmed Fitment
Please note, this information is a combination of supplier provided compatibility data and our workshop expertise. While every effort has been made to ensure the accuracy of this information Progressive Parts Ltd are not liable for abnormalities or inaccurate data. Customers are wholly responsible for checking fitment for their vehicle. More information is available from our Terms & Conditions
UK Shipping
All items marked as available for 'Express Delivery' are dispatched next working day before 3pm.
If you order contains a mixture of 'In Stock', 'Stock Order' or 'Backorder' items, your order may be split to optimise logistics and improve delivery times.
Out of stock items are sourced from our extended inventory and supplier inventory where possible. These may require manufacturing or carry extended lead times which we endeavour to alert you about if the website hasn't already provided an estimated delivery timescale.
DELIVERY INFORMATION
International Shipping
For accurate pricing, please visit the website checkout which will automatically generate a shipping quote to your country.
If your delivery address is outside of the UK, local tax will be removed and you will have to pay import duties and taxes when the shipment reaches your country.
All international shipments may be subject to cross-border inspections by customs authorities while customs policies vary widely from country to country. You must meet any additional charges for customs clearance and we recommend that you contact your local customs office for further information.
DELIVERY INFORMATION
Returns
Progressive Parts operates a 14 day return period from the date of delivery for unused products.
Follow the returns process below for our team to generate you an RMA ID and instruct you to return the goods.
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Stock at Progressive Parts
Delivery timescales are given as estimates in good faith, but cannot be taken as precise or exact information. We highly advise against booking installation/workshop time or engaging in preparatory work until you've received and inspected the goods.
What do our stock statuses mean?
1+ IN STOCK in green stock is readily available in one of our warehouses for express delivery (at the time of viewing).
LOW STOCK in green means we're running low! 1 or 2 left on the shelf so act fast. Over evenings, weekends and bank holidays this stock can move quickly so please bear this in mind.
0 IN STOCK in blue means our primary warehouse does not have unallocated stock, but our UK partners do. Often these can be shipped quickly and efficiently. You'll be notified via the Track My Order page if further delays are unavoidable.
MADE TO ORDER in blue means we've partnered with a supplier which primarily makes their products to order. It's not on our shelf, but your order goes into production immediately.
0 IN STOCK in orange means everybody we work with is unfortunately out of stock. Stock is not available in the UK. The best course of action is to place an order to create an allocation from the next batch arriving.
OUT OF STOCK in red. This product is unavailable to order, for whatever reason we're unable to obtain stock or there is an issue with supply/lead times.
We're tuners too!
Our staff are car enthusiasts, we understand the need for speed... This includes getting your orders out the door as quickly and securely as possible!
In some instances, extended lead times are unavoidable. This is as labour-intensive and frustrating for us as it is for you, please know we are doing our best to facilitate your modification goals. Abuse of our staff or systems will not be tolerated.
Thank you, Team PP
For emissions components this encompasses noise, emissions and balanced back pressure, which have a strong influence on maintaining engine performance (power), and fuel efficiency. Type approval ensures that an aftermarket component will reach, or exceed the performance standard of the corresponding OE part.
Type-approval then, is a certain guarantee that an end user will receive a product of OE equivalent performance attributes.
Products on the Progressive Parts website that meet this approval will be clearly marked or labelled EC or ECE approved.