Ford Fiesta ST Forum banner

spark plugs for stage 3?

9606 Views 21 Replies 5 Participants Last post by  Smokin
Any recommendation s on spark plugs for cobb stage 3? Or are factory plugs fine?
1 - 5 of 22 Posts
My mistake, I thought you were inquiring about a fiesta. Carry on.

But, a quick search on google you would find a thread on a different forum that shows viable options for a colder plug. Just saying. I guess I just am used to people doing research before posting questions. Residual left over from another forum.
Different engine, different requirements.

NGK LTR71X-11....sorry, left out the 7
Those have been proven to not fit and are causing issues. There is no colder plug available for the FiST.
Elaborate please...I wasn't aware the NGK spark plugs I bought, as a direct replacement for the oem plugs, don't fit and cause problems...that's weird
Definitely not a direct replacement as stated by NGK-

JPGC said:
It looks like you are right about it being the wrong plug for these engines. I emailed NGK and got an answer from them. The response is below...


Thank you for your inquiry, however we currently do not have a heat range colder replacement for this spark plug that is quite the exact fit. The original spark plug for this application uses an extended thread shell that part number LTR7IX-11 does not have. The use of the non-extended thread shell can lead to issues with deposit build up on the spark plug that can increase chances of fouling and the possibility of hot spots for pre-ignition.


Rob MacDonald
Technical & Training Specialist
NGK Spark Plugs U.S.A. INC. ||
46929 Magellan Dr. || Wixom, MI 48393
OFFICE: 248-926-7104
And a picture-
See less See more
Well, I wonder why Amazon sells these as direct replacements...looks like I'll be returning these plugs
Fwiw, Amazon is not an auto parts store.
  • Like
Reactions: 1
1 - 5 of 22 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.