Which freakin NGK's are stock replacements for our lightings?
 

OK.... I've got to get this off my chest...

7-8 months ago an NGK Tech Rep via telephone told me that the NGK TR-6 was actually the same heat range as the lightnings stock plugs... I recall very distinctly him saying this and even questioned him. Stating to him that many many lighting owners are writing in several different forums that the TR-6 is a heat range colder than the stock plugs... His response was that the tr-6 was infact the stock plug for the base 5.4 liter but that the lightning had a stock plug which was one step colder than non lightnings and that there for the tr-7 was actually one range colder than the stock lighting plug.....

Any body else heard of this....??

I've always been told that the Ngk Tr-5s were the same heat range as our stock plugs and the Tr-6s were on step colder!:confused: I use the Tr-6s and have had good luck with them!!!:D Jim

Yep what he said :thumbsup:

If you go to NGK web site it says tr-6 are stock for the Lightning
Mike

I guess it's like our Government
Without any notice, and after years of saying one thing
WAM they just change their minds and say something else :devil:

Here ya go

https://www.f150online.com/galleries...003-115389.jpg

i've checked on every cross refererence i could find and tr6's have always been the stock replacement plug. (this was done a year or more ago when i was going to install cooler plugs, on this site i found many an arguement about what tr6's are :rolleyes: )

Some people " felt " since they were copper they were colder, atleast that's what i've heard.

Alot of engines have run well on tr6's but how many engines have blown up on tr6's?

I run tr7ix if it matters and yes they are 1 step cooler than a cross referenced ford (lightning) plug and 1 step cooler then a cross referenced tr6 plug.

They've always been saying that. The only reason people are confused is because JDM has been saying for a long time that tr6's are two steps colder than stock.

TR6=STOCK HEATRANGE

:thumbsup:

TR6=The only plug most people will ever need.

I plan on cleaning out my intercooler in the next few weeks so I figured that would be a good time to change my plugs. My truck is stock except for a JLP air intake, but I plan to add a 4# pulley. Should I go ahead and switch to a plug that is 1 heat range colder? And can I go ahead and make the switch before I actually put on the new pulley?

yup. I would only go colder when using lots of spray.

So what if yer runnin TR55's on a stock L? I gapped mine to .37 per the chart. Runs really well.....no problems.

TR-55 is the stock replacement plug for a standard F-150. V-6 Explorer's use that plug also.

A TR-5 would be one range colder and a TR-6 would be 2 ranges colder vs. a n/a F-150.

The best way to tell if your plugs are the correct heat range would be to pull them right after a pass. If they are orange/brownish they are too hot and you need to step down a heat range. Don't forget to play with the gap either.

As far as NGK's website & reference chart is concerned just look up a '03 Cobra and then a '04 Cobra. They list a tr-55 for the '03 and a tr-6 for the '04. Same car and same engine. I think their data base might need some tuning up.