Spark plugs

MICHAEL D NETHAWAY

MEMBER
2015 FORD FOCUS
2.0L
4 CYL
FWD
MANUAL
36,000 MILES

Hello.I have a 2015 focus st and it needs spark plugs. The manual calls for motorcraft SP-537 plugs. When I go to the ford parts website it calls for SP-527. Can you tell me the difference between the two?The SP-537 plug gap is.051 which seems a little big for the application as would cause fouling over time.I also noticed that the 2014 focus st takes SP-527 but says that the 2015 takes SP-537 not SP-527. Im confused. Did something change with the 2 model years?

Tuesday, April 4th, 2017 AT 3:47 PM

2 Replies

KEN L

MASTER CERTIFIED MECHANIC
50,622 POSTS

Hello Micheal,

Yes the spark plugs can change from year to year which is normal. I would reinstall the exact plug the dealer calls for gap and all. If not the engine will not run the same and you will loose mileage and power.

Please let me know if you need anything else to get the problem fixed.

Best, Ken

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Friday, April 7th, 2017 AT 11:40 AM

STEVE W.

MECHANIC
14,236 POSTS

What makes you think it needs new plugs? Having a misfire or other issue? Those are Iridium plugs that generally are 90-100,000 mile plugs.

The difference in plug numbers
SP-537 - Turbocharged 2.0.051 gap
SP-535 - Non-Turbo 2.0 .051 gap

Or just check on the tag under the hood.

The Ford service interval shows 60,000 miles for severe duty and then only with the turbo 2.0, Normal service shows 100,000 miles.

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