Spark Plug Gap Help

firedog · January 16, 2008

Im doing a plug and wire change on my 00 5.3. I bought the truck used a year ago, it has 92k on it now. Didn't know if the plugs had ever been changed so i just went and got some new ones. I got the NGK tr-55 V-power. I know the sticker under the hood says .60 but I have read on here to go with .44 so thats what im going with. just wanted to make sure that this is correct? The plugs had been changed it had autolite double platinum with the gap at .60. Im in the middle of doing it now. just wanted to get this posted and get some responses on the gap before I finish.

the hammer · January 16, 2008

I love those NGK's that's what I have and they are awesome. Stick with whatever the stock gap is. I actually have to gap mine at .040 for my 2006 5.3L engine. I tried to open them up to .05, but the truck actually ran sluggish, so I went back to the recommended gap from factory.

cmoore74 · January 16, 2008

Lots of confusion on this...

Some say the 0.040 gap is only applicable to the iridium plugs, but if you check the NGK they list 0.044" for all plugs (copper, platinum, and iridium).

If you check AC Delco they list the iridium plug is pre-gapped at 0.040" and should NOT be adjusted, but the copper (rapidfire) plug is listed with a gap of 0.060"

If you search here on TR55 some say 0.040" gap is good while others state 0.060" gap with the TR55's runs great.

There was a recent discussion on this that should come up if you search on tr55.

firedog · January 16, 2008

Yea I searched and got confused. I looked on the ngk website and it said .44. I got it all done and just actually gapped them at .45. It seems to run alright. I took off the negative and put it back on. I drove down the road for the computer to relearn. I didn't get on it or anything.

cmoore74 · January 16, 2008

Please keep us posted on your observations: Engine run smoother? Any MPG change? Any SOTP change in power?

firedog · January 17, 2008

Well I have driven around 50 miles. everything seems ok with the gap at .45. It idles fine, no loss of power, starts right up. Hopefully the gas will be better. It looks good with 9" of lift and 315's but my wallet cries with the frequency of fill ups. I get averaged 12 mpg.