NGK is the clear brand leader in the UK spark plug market with a market share of about 60% outselling its nearest competitor by more than double.  Matthew Beecham talked to Brian Childs, deputy managing director of NGK Plugs (UK) Ltd about trends in the glow plug and spark plug sector.

just-auto: What challenges can direct injection (DI) diesel systems pose for glow plugs?

Brian Childs: Often the DI engines require much longer and slimmer designs due to the difficulty of reaching the combustion chamber and increases in valve size reduce available space for the glow plug.  The port into the combustion chamber is often small to make the chamber walls stronger so this means small probe diameter.

just-auto: We've seen rapid start glow plugs roll out onto the market.  How do you see that evolving in the UK?

Brian Childs: Rapid start systems have been available for some years with great reductions in preheat time.  It is now quite normal not to wait for preheat time especially in the UK's climate before starting the engine. NGK's ceramic AQGS [Advanced Quick Glow System] heats to 900 degrees C in three seconds; these have been used in Nissan engines since the early 1990s.  NGK's AQGS metal glow plugs now achieve 1000 degrees C in two seconds.

just-auto:  In terms of technical specification of glow plugs, what else do you see happening?

Brian Childs: Achieving higher temperatures more quickly with lower power consumption is always demanded by engine designers.  To reduce emissions some engines are now lowering the compression ratio which places a heavier burden on the glow plug regarding its engine starting ability. For example, VAG now use special ceramic designs with temperature of 1350 degrees C.  Strict control via the ECU will be normal and glow plugs may be energized without the driver even being aware if the conditions in the combustion chamber are not favorable for low emission combustion.

just-auto: Even though spark plug technology is improving, can it really catch-up with engine life?  i.e. is a 'life of engine' spark plug a possibility?

Brian Childs: [It's] possible but very dependent on many other factors including the territory of use and type of vehicle. For example, with low stressed engines in the USA plug life far exceeds high stressed engines in Europe.  Engine and driver demands are very different across the globe, even different fuels and oils can have a big affect on plugs.

just-auto: With longer life spark plugs, what is the impact on the aftermarket?

Brian Childs: Longer life plugs are resulting in lower volumes. However, because of the increasing use of precious metals such as platinum and iridium to achieve this, the actual real values of spark plugs are going up to more than compensate for this.

just-auto: Looking at the distribution channels in Europe, what are the big changes you are seeing at the moment? 

Brian Childs: The increasing importance of European Buying Groups is having a real impact on product selection. There is increasing pressure on stockists to carry the correct range. Availability of certain specific types is becoming an issue. Increasingly only good stockists are able to offer the full availability of specific plug types.

just-auto: What's happening to brand names in the market place? Is the power of brands increasing or diminishing with the changes?

Brian Childs: We are increasingly finding that the power of some well-known brands is decreasing. At NGK we believe strongly that today it has become even more the responsibility of the brand owners to invest in the brand to make it strong. Exhibitions, direct mail and advertising are all an essential part of this mix. We believe that our continuing investment in the NGK brand is one of the key factors as to why we are the clear brand leaders in the UK spark and glow plug market as well as in Lambda sensors.

See also: Global market review of spark plugs and glow plugs - forecasts to 2012