I gapped my NGK TR55 spark plugs .040 instead of .050. It was a pain just doing the tune on the passenger side and now I find out I gapped that side wrong.

Will there be a problem or will I be good for many years with this gap?

Thanks guys,

Johnny

 

Are they standard copper core plugs or iridium plugs? I have standard NGK TR55s in my car gapped at .040 and the car runs great. I don't believe you want a gap as large as .050 on standard copper core plugs. You should be fine with the .040 gap.

 

.040 is fine for those plugs. Won't hurt a thing.

 

I agree. I gapped mine at .040

Jake

West Point ROCKS!

 

The gap is good, but depending on how many miles you drive a year, don't expect them to last for "many years".

 

TR55's are copper.

0.040 is ideal for high compression rebuilds, and fine for your stock engine.

They'll open up anyway. I used to use .045 on my stock LT1.