How often are you supposed to change out NGK Tr 55's? I've been running them for about 2 years and change them about every 10-12k. Is this about right? I'm not that happy with them excpet for price, they seem to produce a miss and I have them gapped correctly at .050. What other plugs are good? I don't want anything expensive. How about Autolite's, anything good about them? Part number?

 

I've never really had a problem with the TR55's but looking to try something else too. .050? I always gap mine at .055, stock is .060

 

I run GM 41-985 Iridium plugs. They are now the stock recommended plug by GM for the LS1. I have a heads/cam C5 and they run great. In addition, they are a long life plug...no screwing around changing them out all the time.
Ed

 

You should be able to go 20-30K on TR55s unless you have an ultra rich mixture.

 

I change mine once a year. Normally don't look like they need it. I put 15-20K a year on the car.

 

Had mine in the car for the last 20k miles, and they are fine.

 

Just because they are cheap I change mine every spring. I usually do 5-10k a year.

 

I am getting ready to change mine in a week when i have time. have about 20k on them with a rich tune. I am wondering what they will look like.

 

They are cheap I'll change mine at least once a year probably. I usually check a couple every month, just to see how they are looking.

 

I've went almost 9,000 miles on them, and they are fine so far

 

Unless you spray, they should last as long as your engine does.

 

I totally disagree. Copper plugs are not high mileage plugs.
NGK TR55s are great plugs, IMO, but like all copper electrode plugs these need to be changed more frequently than platinum or iridium plugs.
I have changed my plugs 5 times within 136K miles, each time with TR55s. I've never had a problem that could be attributed to the plugs, AFAIK.
I ran NGK plugs on my flat track and motocross bikes way back when because the other brands would foul out too easily. FWIW.

 

I agree. They won't last as long as your engine does, unless you are only getting 15,000k out of your motor. I'd say ~15,000k is pushing it for a copper plug.

 

Nah, I've seen 'em come out of LS1s after 20-30K miles and look good still. If the tune is good, 30K is totally doable unless you're idling through constant heavy traffic 95% of the time.

 

They might still work after 20-30k miles, but their peak performance begins to taper after about 5-7k. Personally, I wouldn't go much more than 15k if you want optimal performance.

 

I still disagree.

That statement might be true for the colder TR6 plug, but not the TR55. Just my experiance.