NFR-S2k-

First off i'd like to appologize since I know this had been covered before, but i'm doing a valve adjustment and painting my valve cover next weekend and I figured since the plugs will be out ill go ahead and replace them since my car has 60k miles and idk if they have ever been replaced. I'm debating between:

NGK 6988 BKR7EIX-11 Iridium Spark Plug

NGK 7746 IFR7G-11KS Laser Iridium Plug

The 6988's are a bit cheaper but NGK reccommends a 50k service interval vs the more expensive 7746's that NGK says will do 100k and they're both gapped to .043. Ive done some research and people seem to be running both with no problem so I was wondering if I should get the 6988's and replace them every 40k or so when I do valve adjustments or 7746's and replace them every 80-100k. Any advice?

zeroptzero

The 6988's have a tapered ground electrode, and you usually have to gap them yourself as they don't always come pre-gapped.

The 7746's have a typical wide ground electrode with a small disc bonded to the electrode for extra life. These plugs always come pre-gapped. They will have a longer life.

I guess it depends on how much you want to spend and how often you want to replace the plugs, and if you don't mind gapping plugs yourself. I've used both over the years. I tend to run the 7746's as I like the tapered ground electrode feature, and I can gap plugs without damaging the center electrode.

Syncmaster

With such a long replacement interval I'd just get them from Honda. Set it and forget it.

NFR-S2k-

Thanks guys, I'd prefer not to gap them myself since I've never done it before but it looks like ill spend a little more for the 7746's and not worry about replacing them for a long time since I drive less than 5k a year lol.

darcyw

my honda tech friend says to remove the plugs well before the 100K mild service interval, just to keep them from potentially seizing to the threads.

YMMV.

darcy

Sabre

^^ I changed my plugs on the ap1 I used to have at 116k and had no issues with removing any of them.

cosmomiller

I have a DBW (2009) car and based on Billman's recommendation I performed a valve adjustment around 50K miles. Glad I did, the exhaust were tight and if left till 100K I would have torched valves.

Since I was in there I went ahead and replaced the plugs. Looked fine for the milage but I was glad to change them and retorque.

freq

Probably because they were never torqued as well as they should have been from day 1.

zeroptzero

The OEM plat. plugs will experience erosion of the centre electrode as they age, thus the gap grows larger. My factory plugs were over the service limit of .051" gap at 80,000 kms (approx. 50k miles), there was no way they would have made it to 100k miles. I hate the idea of keeping a plug in place for 100k miles without checking them. Iridium plugs don't experience gap erosion as fast as platinum. I put a touch of anti-sieze on the plug threads if they are removed and I'm going to reinstall them.