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So I have a 2000 Ford Ranger XLT 4.0L V6 OHV Engine and I recently replaced the spark plugs. The thing is, the original recommended spark plugs have a gap of 0.52-0.56, which is what is recommended in the Haynes manual. However, I think some time between 2000 and now, the recommended plugs changed to another model, which is factory gapped to 0.44.

The question I have is - which takes precedence? Should I be re-gapping these plugs to 0.54 because that is what is recommended in the shop manual, or should I be making sure the gap is 0.44 because that's what is recommended for these particular plugs?

DucatiKiller
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Paul
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2 Answers2

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You can find the spark plug gap specifications on a sticker that will be either on the radiator support or on the underside of the hood (there are other locations such as the strut towers, etc). This is the gap that should be used when using the OEM spark plugs and even when using an off-branded plug that is a valid replacement for the OEM brand. Here are a few examples of what the sticker will look like.


(source: autozone.com)

Glorfindel
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cinelli
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0

I would verify that the new plugs are in fact the correct ones for the vehicle. If they are a different brand from those originally supplied I would cross reference the numbers just to be sure. If everything checks out, gap the plugs to the plug makers recommendation. The plug is designed with a gap setting that keeps the ground electrode perpendicular to the tip. Opening or closing the gap beyond those specifications results in a larger or smaller gap from one side of the tip to the other.

mikes
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