Auto Trends

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Platinum-

Most long life spark plugs use platinum due to its high melting point. This makes a spark plugs life much greater than the conventional copper, due to the fact that it can hold up so well to the constant heat.

Platinum plug prices go anywhere from around $2 to upwards of $12, and the difference is the amount of platinum used. The more platinum used in the plug, the longer the life it will have. Some platinum plugs today boast they are good up to 100,000 miles.

Iridium-

Iridium is the new platinum. We say this because when platinum came out compared to copper it was superior in many ways. Iridium is said to be 6 times harder and 8 times stronger than regular platinum, which means that spark plugs can have even finer electrodes than ever before and still have excellent wear characteristics.

Iridium is a very costly, so $14 and up per plug is quite typical. Many enthusiasts love iridium plugs and have nothing but positive things to say about them. They will definitely outlast standard plugs and because of their hardness, they will not wear down overtime causing the plug gap to widen and subsequently the cylinders not to fire at their optimum.

Multi-ground Plugs-

While some motors, such as the rotary design specifically require multi ground electrodes, their popularity has extended through many engines. The design of multiple electrodes is meant to limit the amount of wear that occurs of the tip of the firing electrode by offering several several electrodes to fire from.

One of the biggest misconceptions of these plugs is that they must fire from all tips, therefore creating several sparks. This is not the case. There is only one spark that will appear out of one of the tips per engine revolution, which is how these plugs extend their useful life, by spreading the amount of fire time between 2, 3, or even 4 firing tips.

While these plugs do last longer than traditional and come pre-gapped, which makes them easier to install, there has never been any real conclusive evidence of much of a performance gain by the use of these.

Cut-back Plugs-

These plugs bring memories back to the old muscle car enthusiasts. You can purchase these, but often what people do is take a regular set of spark plugs and grind the firing tip back until it is just with the very edge of the electrode.

This design has shown a pretty consistent couple of horsepower (1-3), as well as better throttle response. It does the same thing as all the specialized plug, opens the area of the kernel flame. In fact, it often works better than some of the fancy designs.

Instead of trying to re-shape the ground electrode, you are simply ridding the electrode hang over all together. The only drawback is because you are significantly reducing the contact area of the firing tip where the spark jumps, these plugs tend to wear out a lot quicker than a standard plug.

(to be continued…)