The future of the spark plug market

17 September 2018 | Article

It is well known that the spark plug is an integral part of any internal combustion engine (ICE), which many Western European nations, such as Holland, France and the UK, are increasingly trying to “abolish”, with growing calls for a ban on petrol and diesel engines and a full transition to electric cars.

In Paris for example, a number of limitations on ICE vehicles are already in effect: the city has car-free zones and regularly holds car-free days. In addition, cars and motorcycles manufactured before 1997 are not allowed in the city centre, and violators pay fines of up to 70 Euros.

Electrification Vision

The consequences of a push for electric vehicles

At the same time, leading industry experts admit that if all standard ICE vehicles were replaced with electric cars, all the power stations in the world put together would not be able to produce enough electricity to power them. Consequently, the transition from petrol or diesel to electricity does carry significant costs. After all, the infrastructure will have to be completely overhauled. This will demand the construction of new power stations, which will most likely be nuclear. Also, the systems in place for recycling hazardous batteries are far from perfect.

While all these issues are being worked out, internal combustion engines will continue to be manufactured and improved. And the most important areas for improvement are dictated by the current needs of the day: the engine’s environmental features and operating parameters. In this context, a feature like the spark plug plays a very important role.

The evolutionary apex of spark plug design

Fans of the DENSO brand know that high-performance, ultra-fine iridium centre electrode plugs represent the evolutionary apex of this automotive component. The thinner the electrode, the easier the flame growth and more stable the combustion. Many DENSO Spark Plugs have the thinnest centre electrode on the market at only 0.4 mm.

As one of the hardest materials with a high melting point, iridium offers the advantage of high density and high corrosion resistance even at temperatures of several thousand degrees. So compared to regular nickel plugs, iridium spark plugs have much higher capacities. In addition, they help improve the car’s environmental safety parameters, decrease fuel usage and make the engine more responsive.

Denso Spark Plug Packaging

Progress marches on – and the car market is no exception

Vehicles are growing in complexity; automotive component requirements are becoming more stringent; engine space is decreasing; and consequently, the components must become smaller, while at the same time, their performance must continue to improve. What this means for spark plugs, is that they will continue to shrink, while standard (nickel) plugs, with their inferior performance, will continue to give way to more effective iridium plugs.

Experts know that as an engine’s coefficient of performance and fuel efficiency increases and as emissions decrease, the temperature in the combustion chamber goes up. But an ultra-thin electrode can only withstand the high temperatures and corrosive environment of the combustion chamber if it is made of suitably durable materials. That is why the assembly lines of many car companies have already fully transitioned to the use of iridium spark plugs. Today, we can confidently say that iridium, this champion of durability, corrosion resistance and strength, is the perfect material for spark plug electrodes, even when compared to platinum. DENSO Iridium TT spark plugs have a life span of 120,000 km — longer than the average life span of a car under its first owner.

What does the future hold?

We are inclined to expect that engine size will continue to decrease. This means that spark plugs with a finer electrode than those on the market today will become standard in the future. Spark plugs made using precious metals will obviously grow in popularity. As European regulations continue to be tightened, limits on emissions will also keep becoming more stringent, forcing car engine manufacturers, in turn, to use all available resources to meet these limits. To this end, fine wire electrode spark plugs alone can produce the necessary operating parameters, regardless of how long they have been in use.

As for the ICE, we should not write it off as of yet. It can still offer a certain level of durability and flexibility, along with room for improvement. And it is specifically advancements in the spark plug technology that can make it even more environmentally friendly, economical and agile.

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