The chief executive of German auto parts maker Bosch, the world’s leading diesel-technology developer, insists diesel cars are good for the environment.
Volkmar Denner said Tuesday that diesel vehicles are “air-purifying machines” because fewer particulates are released from exhaust pipes than are sucked in by their engines from the air.
He added that European and German emissions reductions targets for 2020 and 2025 can only be reached with a large contribution by diesel, since emissions-free electric vehicles are too costly and will remain out of reach for most buyers.
German investigators are looking into whether Bosch is culpable in the emissions-rigging scandal. The Stuttgart-based company supplied emissions-control software and hardware for VW diesel engines at the heart of the scandal.
Mr. Denner denied that Bosch was responsible for wrongdoing in an interview with Handelsblatt at the recent International Consumer Electronics Show in Las Vegas. In the interview, he strongly criticized the use of the term “Dieselgate.”
Bosch insists Volkswagen, not the parts supplier, is responsible for system integration and the decision to use Bosch’ technology to evade emissions control tests. VW programmed up to 11 million diesel autos to turn on full emissions controls only when they were being tested. Once tests were over, the software switched off the emissions controls, which permitted better performance.
In car assembly, system integration includes additional components such as catalytic converters, which Bosch does not manufacture.