I tightened mine up today, they were in the car for about 2500 miles, I installed them at 18 ft lbs. They turned a small bit at the new tightening spec., but they weren't loose. Number 3 plug turned a bit more than the others for some reason. Thanks for the info Billman and Jordan

 

Stopped by Auto zone today and they said that Honda no longer recommends the 7772 and instead changed to NGK Iridium 7746. Is this accurate?

 

The NGK BKR7E copper is a good plug too.

Cost=$2ea.

\rlr
Carolina

 

Iridium should last longer than platinum.

 

While tempting, I've always been a firm believer in "you get what you pay for" soooooo eh?

 

Copper is actually a better conductor of electricity than platinum or iridium, the thing is that they wear faster. To be honest the price difference between platinum and iridium plugs are non-existent and factually iridium plugs should last longer.

 

Here's a video tutorial:

http://www.youtube.com/watch?v=Q5-7FaQSfP4

 

Great guide and thanks for all the info. Just picked up the NGK Laser Platinum plugs ready to fit over the weekend with a new oil filter and oil change.

Thanks again guys

 

The conductivity benefits aren't relevant. The platinum and iridium plugs have copper cores which do the bulk of the current carrying. The additional resistance from going through a platinum/iridium tip is more than offset by the fact that they spark more easily because they maintain a sharp edge better.

I remember reading that in addition to better geometry, iridium (and platinum) as a material sparks more easily but I currently can't find it online.

When I changed my plugs last time, I went for iridium ones, because as you said the price was close and the iridium plugs should last longer.

 

Also, the smaller diameter electrode of the platinum and iridium plugs makes for a more concentrated spark, versus the copper electrode one.