Sorry Jerry, I think the thread was referring to the colder plug having to do with starting better and better fuel burn with some of the goofy fuel mixes these days.
Running a "colder" heat range plug, with everything else equal, is unlikely to improve starting or fuel burn characteristics. The heat range of a plug refers to the ability to maintain the temperature of the actual firing tip in the optimum range to prevent both cold fouling and hot preignition / accelerated erosion. A "colder" plug design transfers the heat from the tip to the shell and then the head faster than a "hotter" design. That's all the heat range is about and has nothing to do with actual combustion temperatures or engine temperatures.
The NGK Iridium plugs that were most likely the subject of the threads you read have a very fine wire center electrode made of a material that resists erosion better than the standard material, similar to the way platinum electrodes are also used to extend the life of plugs. If you keep the edges of the electrodes sharp and the air gap consistent (less erosion), the amount of energy required from the ignition system to fire the plugs remains lower over time and the spark is more consistent. As the edges become more rounded and the gap grows the system is required to produce more voltage to produce a reliable spark. So installing a new set of these plugs should make for a more consistent spark that can in fact improve starting as well as normal running with todays lean mixtures and reformulated fuels. But the same can usually be said of a brand new set of standard plugs too. The real difference is how long the platinum or iridium electrodes can go before performance starts to suffer compared to standard plugs.
If you are the type who changes plugs every 5000 miles, the longer life platinum or iridium plugs are a waste of money. And all those testimonials from people who change from standard plugs to one of the platinum or iridium plugs tend to be suspect at best. I would expect improvement when replacing an old worn plug no matter what I screwed into the hole. It doesn't necessarily have anything to do with the platinum or iridium electrodes, it's just comparing old worn stuff to brand new stuff.
Jerry
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Topic: 2014 Sparkplugs? (Read 3275 times)