... they are also 1 heat range colder but use a silver center electrode instead of the typical iridium used in most of today's spark plugs. Silver is supposedly a better conductor, but does not last as long.
A lot of people on M6G were raving about them and they were under $36 delivered, so I gave them a shot.
Don't really notice a performance or MPG difference but gap on factory plugs varied between 0.029~0.031" (should be 0.028), so I'm glad I swapped them out.
The Brisk's were not "pre-gapped" like Adam does, so you DO need to check/set gap before installing.
. A “cold” plug transfers heat rapidly from its firing end into the cooling system and is used to avoid core nose heat saturation where combustion-chamber or cylinder-head temperatures are relatively high. A “hot” plug has a slower heat transfer rate and is used to avoid fouling under relatively low chamber or head temperatures. What’s confusing is that a “hotter” (higher performance level) engine requires a colder plug because more power equals higher cylinder temperatures.
If your car is stock or close to stock their is no benefit. If you are running a tune with more timing and boost the colder plug may help prevent detonation from occuring which would allow you to get the maximum power the engine has to offer.
One heat range colder is not much and is likely within the variability between different manufacturers specified plugs.
Yes I know this is a very old thread, but it is the only place I found that came close to answering my question. So I bought the NGK 6510 spark plugs. They are pregapped by the factory to .043. According to this link, they should be gapped .0275 for 91/93/E30 and .0245" for E85? Is that correct?
The spark plug design determines its ability to remove heat from the combustion chamber. The primary method used to do this is by altering the internal length of the core nose. In addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges.
*When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, keeping the firing tip cooler.
*A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as adding a turbo or supercharger, increasing compression, timing changes, use of alternate fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature, necessitating a colder plug.
A good rule of thumb is, one Heat Range colder for every 75–100hp added.
In identical spark plug types, the difference from one full Heat Range to the next is the ability to remove 70°C to 100°C from the combustion chamber.
The Heat Range numbering system used by spark plug manufacturers is not universal.
For example, a 10 Heat Range in NGK is not the same as a 10 Heat Range in Champion nor the same in Autolite.
Some manufacturers numbering systems are opposite the other - for Champion, Autolite and Bosch, the higher the number, the hotter the plug. However, for NGK, the higher the number, the colder the plug.
It is not recommended that you make spark plug changes at the same time as another engine modification, such as injection, carburetion or timing changes. Performing too many modifications or tune-ups at once will lead to misleading and inaccurate conclusions if any issues occur (an exception would be when the alternate plugs came as part of a single pre-calibrated upgrade kit).
When making spark plug Heat Range changes, it is better to err on the side of too cold a plug. Running too cold a plug can only cause it to foul out, whereas running too hot a plug can cause severe engine damage.