Although many motorists and technicians prefer to stick with the same brand when replacing spark plugs, there’s nothing on the label that limits a particular brand of plug to a particular vehicle make or model. In other words, any brand of spark plug can be used in any vehicle make or model application assuming the plug has the correct dimensions, design and heat range.
The engine won’t know the difference. All spark plug manufacturers cross-reference their plugs with other brands so their brand can be interchanged with other brands. For most applications, there are usually a variety of brands that are interchangeable. For some more specialized applications, however, the selection may be much more limited, and there may only be one or two brands that list a spark plug for that application.
What’s really important is making sure your customers get the correct spark plugs for their engine regardless of the brand. If a particular brand of spark plug is not listed for a given application, don’t try to second-guess the manufacturer. If they don’t have a spark plug for the engine, there is a reason why.
They may not have a plug with the correct electrode configuration, reach or heat range. Plugs that look very similar externally may be very different internally, and may not perform properly if installed in an application they are not intended for.
A plug that is too hot increases the risk of pre-ignition and detonation while a plug that is too cold may experience fouling problems.