Denso Spark Plug Set To Suit 300HP - 420HP XR5 / MK2 RS

Spark plugs to suit tuned power Focus XR5 (ST225) / MK2 RS.

Premium Denso Iridium Power. Through patented technology, including a 0.4mm diameter centre electrode - the Iridium Power plug produces the hottest, most concentrated spark with the lowest voltage and outperforms any plug today.

1 step colder than stock XR5 spark plugs, same temperature rating as MK2 RS spark plugs - these are perfect for a 300-420hp vehicle

Tried and tested

While it's possible to replace a single spark plug to diagnose a fault, it's generally recommended to replace all 5 at the same time, especially if they are the last known change is unknown. This helps ensure consistent performance and reduces the likelihood of another plug failing shortly after.

Replacement intervals:

Stock vehicle: Replace the spark plugs every 60,000 km. This is a good preventative maintenance interval for the OEM plugs.

Lightly tuned (Stage 1/2): Every 20,000 to 30,000 km is a sensible interval as higher boost puts more demand on the plugs.

High-power or track-driven cars: Expect to replace them every 10,000 to 20,000 km, depending on the tune and how the car is used.

Note:

Pre gapped to 0.8mm out of the box - factory gap spec: 0.7 mm

Tightening sequence - same as stock spark plugs Ford recommends 28nm

If a torque wrench is unavailable: thread spark plug into the cylinder head until it's hand tight then turn an additional 1/4 turn to crush the sealing washer.