Hi, hoping for sone help. I have a 21 plate mild hybrid 3cyl fiesta st-line. Went to swap plugs at this service - but the bosch replacements are a few mm longer? Obviously I didn't put them in - does this difference matter? Are the plugs going directly into a cylinder that could risk collision or maybe just a  pre ignition chamber?

Bosch plugs number is shown in image, as is difference in length? Can anyone confirm if I have the correct part number.

Thanks for any advice

Wrong plugs. Get the correct ones.

Wrong profile, yours not the plugs 🤣

Cheers updated profile too lol.

Those bosch ones came back as compatible under a reg check online. Are the ebay links on here better and more accurate do you know?

1 hour ago, Jygee35 said:

Cheers updated profile too lol.

Those bosch ones came back as compatible under a reg check online. Are the ebay links on here better and more accurate do you know?

Even ebay state that you cannot rely on their links!

It looks as if you are comparing the overall length of the plug, rather than the length from the tapered seat to the tip, which is the distance that matters. Compare tip (electrode) to tapered seat, and if this is the same then you have the correct plugs.

Thanks for reply - I have other images showing  both seats at the same height, and the electrode is still genuinely a few mm's higher, so the tip would definately  be further into the cylinder. I didn't buy these on e-bay to be fair, but from ECP so ill look around.  Thanks 

Several Ford dealerships have eBay shops and I have bought genuine parts through them. In the case of an Ecoboost, I would buy genuine.