Spark Plug Cross Reference Chart: Technical Information for Switchable Brands

January 27, 2012

A spark plug cross reference chart can be used when you need to replace a spark plug but cannot find the exact model your car came with. There are comparable brands out there that offer interchangeable makes of spark plugs you can use. Understanding these charts may seem like a difficult task, but you can do it with a little technical knowledge by your side. Here are some tips to help you understand how those charts work and what they can do for you.

Understanding Compatibility

You have to get the right kind of brands for the spark plugs you put in a car. Different areas of the world use different makes, and that will have a huge impact on fit and performance. Most GM cars use AC plugs, and Ford uses Motocraft. Most Asian manufacturers will either use Denso or NGK plugs. This is just a standard, but it may give you an indication of what to watch out for. Bosch is a rather universal maker for spark plugs, but it may not be compatible with all vehicles. Other models you may see in racing engines are Autolite and Champion.

Changing the Material

As long as you stay within the same company, you can change the grade of material you use with the spark plugs. the grade of material will determine the longevity of the plugs, but it will also be a factor for the cost. You can get platinum plugs for the basic models, and the next step up is double platinum. These plugs work the same but they are stronger because of the extra metal. You can also consider iridium plugs when you go to make a purchase. You just need to make sure the ones you get are made for your car.

Knowing When You Need New Plugs

If you are going to look at a reference chart, you will need to do a spark plug diagnosis to determine what is wrong with your plugs and which ones need replacing. Factors like the age of the plugs and the spark plug heat range will come into play for this. Listed below are a few indicators you can watch for to know when you need a replacement:

If you notice large deposits of hardened chemicals on your spark plug, you will need to remove them to ensure fuel quality is good for the car. The deposits can come from zinc, sulfur, iron and many other elements that are present in your motor.

If your spark plug has overheated, the insulator cap on it will look glossy or glazed. If you notice this, you'll need to find a replacement so you can have a properly working cap.

If you notice large breaks on the spark plug, it's usually an indication of shock that resulted from sudden temperature changes. You may want to diagnose other problems with the engine if this is the case. Replacing the part will make up for the broken pieces.