Quote:
|
Originally Posted by Brucelee
I am going to disagree and suggestg iridium plugs by DENSO.
Great stuff.
|
Hi,
Curious why you would say so. What makes them so good?
More spark is not better than
enough spark to ignite the A/F Mix, despite all the marketing hype.
And, there is no standardization in the Heat Ranges of the various Plugs on the market, only an approximation. In each Plug, the heat range is a measure of the spark plug's ability to remove heat from the combustion chamber.
In
identical spark plugs, the differences from one heat range to the next is the ability to remove
approximately 70°C to 100°C from the combustion chamber. But, all Plugs must operate between 450°C to 850°C. If the tip temperature is lower than 450°C, the insulator area surrounding the center electrode will not be hot enough to deter fouling and carbon deposit build-ups, causing misfires. If the tip temperature exceeds 850°C, the spark plug will overheat which can cause the ceramic around the the center electrode to blister as well as the electrodes will begin to melt. This may lead to pre-ignition/detonation and expensive engine damage. But, remember, the Heat Ranges are approximations and only apply to
identical Plugs from the same manufacturer. It is not possible for the layman to access the data for a different Plug to see if it exactly matches the OEM Spec., though some Plugs may have identical specs. And, you cannot be sure the Plugs possess an identical Index once installed in the Head.
If longer Life, well I'm from the school which says to change your Plugs every two years regardless of Mileage. Spark Plugs are subjected to some of the greatest stress produced by the engine (think of the Heat Cycles they must endure and how many times they
work/min. of Driving). Spark Plugs are really pretty fragile and are subject to any number of bad things such as broken electrodes, carbon arcing, and cracked porcelain.
They simply should not be installed and forgotten, they need some semi-regular inspection. Since they are relatively cheap to replace (especially for the DIYer), and since inspection amounts to changing them (especially on the Boxster) anyway, you might as well get a fresh set in there while you're at it - it justifies all the work of jacking up the car, removing the undercover, coil pack, and such.
If you think of it, some people will change less important, but maybe more expensive, items at a much shorter or regular interval than their plugs, that doesn't make much sense to me. You'll spend more $$ on a K&N Filter or intake mod, than you'll spend on a
lifetime of Plugs, even at a 2-year change interval - that just strikes me as odd, but it's probably because people generally aren't that knowledgeable about Plugs and don't appreciate the value of a fresh set...
Happy Motoring!... Jim'99
Linear Mode
