EU customers, please read before purchasing

Important Info

Search our store

39 reviews

2536-ISP-AA

Iridium Spark Plug Set [Mk3 Focus RS]

EcoBoost engines running substantially higher boost pressure or increased levels of tuning compared to the OE power output can experience reduced spark plug life resulting in lower engine performance, misfires and rough idle.

Increased wear is typically seen in the form of increased spark plug gap and degradation of the electrode. Using spark plugs that are optimised for increased power ensures maximum performance.

Extensive in-market validation at extreme boost / cylinder pressures was undertaken to ensure optimal performance was achieved, whilst also making sure  reliability and drivability wasn't compromised in colder ambients.

Each set is supplied pre-gapped by mountune to optimise the setting and allow for easier end-user installation. 

The NGK LTR71X-II is one step colder than the original spark plug.

Applications:
Focus RS 2016-2018

Features:
  • Smoother acceleration
  • Perfect for high boost applications
  • Supplied pre-gapped by mountune

Please note:Supplied in a pack of 4 plugs.

Customer Reviews
5.0 Based on 39 Reviews
5 ?
100% 
39
4 ?
0% 
0
3 ?
0% 
0
2 ?
0% 
0
1 ?
0% 
0
Customer Photos
Write a Review Ask a Question

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

Filter Reviews:
    RS
    28/10/2021
    Ralph S.
    Switzerland Switzerland
    Super fast Delivery

    Everything okay, thanks

    mountune Iridium Spark Plug Set [Mk3 Focus RS] Review
    CB
    20/10/2021
    Clive B.
    United Kingdom United Kingdom
    Iridium spark plugs mk3 Focus RS

    All ready gaped.easy fit. notice the difference when cold at startup

    DR
    18/10/2021
    Darren R.
    United Kingdom United Kingdom
    Better Performance

    I had a mountune 375 package installed, utilising the standard Ford plugs which were 1k old at the time. Car did not feel as strong as I would have expected and I tried a couple of different checks, including changing for another set of RS plugs from the dealer. Since installing the uprated plugs the car is transformed. Better idle, better low down pull with a smoother transition onto boost. 4k plus in the rev range, it's like a different car. I would suggest the plug are part of the 375 upgrade and a replacement over standard!