July 3, 2007 The humble spark plug is an engineering solution that has now stood the test of over 100 years production. One of the earliest patents for the spark plug was taken out by Robert Bosch in 1898, and the Bosch company was the first to produce the commercially viable high-voltage spark plug that made internal combustion engines possible. A century later, as an extraordinary 10 billionth spark plug rolls off the Bosch production line, the company has become a global powerhouse with interests in automotive parts and systems, power tools, building, packaging and safety, not to mention the invention of ABS braking and traction control systems. And with Bosch fuel injection feeding both the Audi and Peugeot diesel racecars that finished first and second at Le Mans, the company seems set to play a key role in the high-powered, fuel-efficient second coming of the diesel engine - and it's all built on the success of the modest spark plug.

The 10 billionth Bosch spark plug has just been produced at the company’s Bamberg plant in Germany, making Bosch the world's most prolific manufacturer of spark plugs. The vast majority (8 billion) were manufactured at the Bamberg plant, which was established in 1939, while the remaining units were produced at other plants around the world. Laid end-to-end, the Bosch spark plugs would form a chain stretching for more than 560,000 kilometres, circling the equator approximately 14 times.

A century ago, Bosch produced just a few hundred spark plugs per annum - today, the figure is more than 300 million produced in factories across the world. Bamberg is still the primary plant for Bosch spark plug production and sets standards for all other Bosch spark plug plants. Bosch factories in India, Brazil, China and Russia also produce spark plugs for the local automotive industries and markets.

Bosch unveiled its first spark plugs combined with a high-voltage magneto more than 100 years ago, and patented the innovative system on 7 January 1902. Bosch's reliable ignition system for engines with ever-increasing speeds finally solved what Carl Benz described as the ‘problem of all problems’ in early automotive engineering. The spark plug, in combination with industrial manufacturing techniques, opened the way for the surge in vehicle production experienced during the following decades resulting in more affordable vehicles.

Today, constant developments in Bosch spark plugs as integral system components have made a significant contribution toward more economical, cleaner, and more efficient fuel combustion, as well as to more reliable engines and catalytic converters. Despite the significant increases in performance, the service life for normal spark plugs today is around 20,000 to 30,000 kilometres - roughly 20 to 30 times higher than the spark plugs of a hundred years ago.

In recent years, Bosch has demonstrated the ongoing potential of its flagship product, adapting it to the ever-changing developments in engine technology, such as 4-valve, lean-burn or ultra-efficient direct fuel injection. The versatility of Bosch spark plugs is the result of design modifications and the use of special metals such as platinum and iridium, or yttrium. By varying the number, design and structure of the electrodes, many adaptations are possible - incredibly, there are 31 different electrode configurations in the company's current spark plug catalogue. All these factors allow engines to comply with ever stricter emissions targets while at the same time increasing performance and efficiency.

With a long history of expertise in the field, and its intensive spark plug development projects in close collaboration with almost all vehicle manufacturers, Bosch remains one of the world's leading suppliers in original and aftermarket equipment and is the market leader in Europe. Many top vehicle manufacturers use Bosch spark plugs as standard: Alfa Romeo, Audi, BMW, Cadillac, Citroen, Daewoo, Daimler-Chrysler, Fiat, Ford, GM, Lancia, Mitsubishi, Opel, Peugeot, Porsche, Renault, Saab, Seat, Skoda, Ssangyong, Suzuki, Toyota, Vauxhall, Volvo and Volkswagen are just some of its clients. Because many of the latest engines now have bespoke spark plugs, the range has grown to more than 1,250 variants. In total, well over 20,000 types have been developed within the last 100 years.

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