Influential factors in the product development
The worldwide discussion about environmental and climate protection, limited fossil resources and increasing petrol prices has altered public awareness considerably. Additional efficiency strategies for combustion engines, the use of new technologies and CO2-saving alternative fuels are demanded of modern engine concepts.
This presents great challenges for the automobile and supplier industries and has direct influence on the development of spark plugs, glow plugs and lambda sensors.
More efficient combustion and reduction of harmful emissions
Modern engines must fulfil increasingly strict environmental guidelines (keyword: Euro standards). Therefore, a great challenge lies in engine efficiency and the reduction of consumption as well as the reduction of harmful emissions. Through the development of wide-ranging technologies for spark plugs, glow plugs and lambda sensors, NGK supports the vehicle manufacturers in their respective strategies in the best possible way.
The engine bay of petrol engines is becoming increasingly smaller - with the same output. This is a trend referred to as "downsizing". Consumption and environmental pollution are reduced. In order to ensure that enough output is available, such engines frequently run with turbochargers and/or compressors. Intake and exhaust valves require a great deal of space in these engines, as do the coolant passages. This places special demands on dimensions, ignition reliability, thermal behaviour of spark plugs, etc.
Alternative fuels, e.g. gas operation
More and more engines are converted to "bivalent operation". That means: They can run on conventional petrol or a gas (LPG/CNG). For the spark plugs this means complicated conditions in regard to temperature load and ignition.
The replacement intervals defined by automobile manufacturers for spark plugs vary between 30,000 and 120,000 kilometres. This represents a challenge, as each ignition spark wears down a microscopic amount of material. Through this "spark erosion" the ignition voltage requirement increases by approximately 500 volts per 20,000 kilometres. These requirements are met through the development of special spark plug technologies.