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31 reviews


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.

Focus RS 2016-2018

  • 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 31 Reviews
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Filter Reviews:
    Jason B.
    United Kingdom United Kingdom
    Iridium Spark Plug Set

    Easy to install and vast improvement when running more power. Iridium Spark Plug Set

    Dave W.
    United Kingdom United Kingdom
    Great product as usual

    Great the car feels much better

    United Kingdom United Kingdom
    Focus RS v3 Spark Plugs

    Installed along with a replacement Air Filter at 3yr Service and although early days noticeable improvement