Maybe you haven’t thought about spark plugs much lately, but NGK’s SEMA announcements show the technology continues to drive ahead

Drag-racing driver Megan Meyer, sponsored by NGK Spark Plugs,
greets automotive-industry attendees of the 2018 SEMA Show
at the NGK booth.

By Bill Hayward

If you don’t spend much time thinking about automotive spark plugs these days, don’t feel guilty. You’re in good company. Thinking about spark plugs a lot less often is something that has been to some extent encouraged since, say, the 1980s.

That said, some of us are old enough to still remember a time when folk wisdom, perhaps with a push from the auto repair industry, held that an “annual tune up” that included changing ignition parts like plugs, points, and ignition wires, was an essential element of automotive maintenance.

However, in terms of the actual service life of spark plugs and the maintenance recommendations of automakers, for many vehicles it has been even longer since that folk wisdom has reflected reality.

For example, a New York Times article from January 10, 1975, references original-equipment spark plugs that were “designed to last at least 22,500 miles” for a 1975 Chevrolet Monza 2+2 equipped with a 262 cubic-inch small-block V8.

That’s a good deal more than the 13,474 miles that, according to the U.S. Department of Transportation, gets clocked on the average car each year. And since the 70s, service intervals for spark plug replacement have grown significantly longer—sometimes in excess of 100,000 miles, depending on manufacturer recommendations and other factors like driving conditions.

Of course, there is always the “individual results may vary” disclaimer.

Have you ever been the proud owner of an old, oil burning jalopy? In the days before the catalytic converter transformed it into veritable death sentence for an engine—not to mention a possible fire hazard—oil burning could be a mere nuisance problem.

In an old car with no catalytic converter, many drivers would continue to deal almost indefinitely with a car that burned oil, as long as they were willing to keep a constant eye on the dipstick and add oil as needed. But an oil-burning problem could also foul a new set of spark plugs beyond redemption in just a few short months, if not sooner, making the replacement need a lot more frequent.

An oil-burning jalopy could seem to run with a new lease on life for a short time after swapping in a new set of plugs. But before long, the oil burning would set back in and that tired-out hoopty feeling would return.

For newer cars with sound engines under normal everyday driving conditions, however, there is indeed legitimate reason to no longer think of spark plugs as a component that needs frequent replacement. And advances in technology continue to extend the service life that you can expect.

With spark plugs, as long as other factors such as engine condition are equal, service life comes down to the metal composition of the electrode tip. The properties of different metals, like melting point, electrical conductivity, and resistance to oxidation, work together to affect issues like how efficiently a spark plug ignites the fuel in an engine’s combustion chamber and how long the plug can continue to operate efficiently and deliver good performance.

The baseline option is still the copper-tipped spark plug. Copper-tipped plugs are the most economical and were the original-equipment standby in old classic engines from the past that we know and love.

As technology continued to evolve, responding to market pressures ranging from interest in increasing horsepower to demands for greater fuel efficiency and a reduced maintenance burden, the use began, in spark plug electrode tips, of alloys of more precious metals like nickel and platinum.

Although platinum-tipped plugs have been around since the 1960s, their widespread use in production cars began in the 1980s. Today, platinum-electrode plugs are original equipment in over 90 percent of contemporary vehicles, according to Just Auto.

Meanwhile, spark plug technology has continued to advance beyond platinum. For example, according to Counterman, leading manufacturer NGK introduced spark plugs tipped with the precious metal iridium in 1994, harnessing advantages such as increased hardness and melting point compared to platinum.

And at the 2018 SEMA show last week, Danielle Orlando, NGK’s general manager of brand marketing, announced that the company is “redefining spark plug technology for the next decade” with the introduction of ruthenium-tipped spark plugs.

According to Orlando, the NGK Ruthenium HX plugs offer the advantages of higher ignitability, enhanced oxidation resistance, twice the service life of the company’s iridium spark plugs, and four times the service life of nickel plugs.

So much for the notion of “planned obsolescence.” In an age where we see early adopters lining up to get the latest iPhone, it’s refreshing to see, in the spark plug category, an industry whose technological advances actually push toward decreasing the frequency with which the consumer needs to think about its products.

The new line of ruthenium spark plugs includes 25 part numbers for over 200 million vehicles currently in operation for over 93-percent market coverage, according to NGK.

NGK also announced at SEMA 2018 the debut of what the company says is the industry’s first dataset of replacement interval guidelines to be integrated into their online part-finder system as well as feeds of ACES data provided to parts and service counters across the industry.

The annual tune-up concept is long gone for most motorists, but beyond that there is a degree of variability among manufacturers in just how frequently we need to think about our spark plugs. So a service from NGK that adds some clarity and convenience to the question could be a welcome change.

NGK's continued advances in the ignition domain come even in the face of a 2017 announcement, as reported by Reuters, that the company was shifting in the direction of solid state battery production in preparation for an electric-vehicle-dominated future. Perhaps that's a sign that we internal-combustion aficionados can look forward to still being able to enjoy our gasoline rushes for at least a few more years.

Also at SEMA, NGK Spark Plugs announced their sponsorship of the 2017 NHRA Quickest Sportsman Female Driver Megan Meyer, a top alcohol drag-racing driver, who was on-site at the NGK booth at SEMA.