Platinum is writing automotive history

The new NGK semi-surface ignition type spark plug for all Volkswagen VR 6 engines.

Since August 1995 Volkswagen fits its VR6 engines for models Golf, Passat, Sharan, Vento, and the bus T4 with the new NGK semi-surface ignition type spark plugs with platinum center electrode type BKR 5 EKUP. With this high-tech spark plug a platinum ring is welded by laser, employing a special production process, onto the center electrode. By means of this particular technology the service life of the spark plugs was exactly doubled from 30,000 km to 60,000 km now.

At the same time, all the advantages of the proven semi-surface ignition concept (smooth idling, reliable ignition, and protection of catalytic converter) are maintained.

Why VW has opted for the semi-surface ignition type spark plugs by NGK.

Extraordinary factors, like the extreme traffic prevailing today, can cause carbon deposits on normal spark plugs. The deposits developing on the insulator tip of the spark plug produce an electrically conductive connection between the center electrode and the inside of the spark plug shell. This can cause bypassing and, therefore, misfiring, which will result in irregular engine idling.

The outcome: Unburnt fuel-air mixture could get into the catalytic converter and damage this by overheating.

How the semi-surface ignition concept works.

The principle of the semi-surface ignition type spark plug is based on the idea that the ignition sparks creep across the projected insulator tip and wear off possible carbon deposits. Only then does the spark flash from the insulator tip to the ground electrode and the fuel-air mixture is safely inflamed.