Germany’s Robert Bosch reveals a new diesel technology the multinational supplier claims to reduce emissions of oxides of nitrogen, a harmful byproduct of diesel that is expensive to treat, to one-tenth of the legally permitted limit set for 2020.
“There’s a future for diesel,” Bosch CEO Volkmar Denner says in a statement announcing the breakthrough alongside the organization’s annual meeting in Stuttgart. “Today, we want to put a stop, once and for all, to the debate about the demise of diesel technology.”
Bosch says its new technology, on average, emits no more than 13 mg of NOx per kilometer, which is far less than the 120 mg permitted by European standards after 2020. Test vehicles in real-world conditions see reductions to as little as 40 mg. It uses off-the-shelf parts so there is no cost escalation and it is available to customers immediately.
“Bosch is pushing the boundaries of what is technically feasible,” Denner says. “Equipped with the latest Bosch technology, diesel vehicles will be classed as low-emission vehicles and yet remain affordable.”
The future of diesel, a fuel-efficient technology that delivers high torque in commercial vehicles and light trucks and sportiness in smaller cars and CUVs, has been in question since the emissions-cheating scandal broke at Volkswagen in 2015.
U.S. officials discovered the German automaker used a software program that would enable the emissions controls of some its diesel engines to meet local standards during testing by regulators, but then disable the system during real-world use for heightened fuel efficiency and performance at the expense of NOx output rising to illegal levels.
VW paid $20 billion in fines and owner compensation for the cheating. Several executives responsible for the cheating also were arrested. The scandal nearly toppled the world’s largest automaker, and it since has shifted away from diesel to electrification.
Bosch also was implicated because it wrote the emissions-control software and supplied it to VW. For its role, Bosch paid $327.5 million in compensation to owners. It did not admit wrongdoing in the settlement with U.S. regulators and continues to cooperate with investigations elsewhere in the world. No Bosch engineers were arrested but its reputation was damaged.
Bosch’s new technology, which it developed independently, combines advanced fuel injection with a newly developed air-management system and intelligent temperature management for historically low diesel-fuel emissions.
In the past, NOx emissions reductions in diesel vehicles have been limited by the individual driver: dynamic driving styles require an equally dynamic recirculation of exhaust gases, Bosch explains. The new technology uses a turbocharger from BMTS Technology, formerly Bosch Mahle Turbo Systems, that is optimized for real-driving-emissions performance. It reacts quickly with high- and low-pressure exhaust-gas recirculation, making air-flow management highly flexible so drivers can travel at any speed without a spike in NOx emissions.
Temperature plays an equally important role, the supplier says. To ensure optimum NOx conversion, exhaust gases must reach a minimum of 390° F (200° C). But during urban driving, temperatures frequently fail to reach that level, so Bosch implements a sophisticated thermal-management system to actively regulate exhaust-gas heat to ensure the system stays hot enough to keep emissions low.
Other notable technical details include combining the particulate filter and SCR catalyst into one unit and locating it closer to the engine to scavenge heat.
But the supplier says it can go further in cleaning up tailpipe emissions from combustion engines with artificial intelligence, where excluding carbon dioxide there would be no impact on ambient air.
Bosch also announces plans around cleaning up CO2 emissions, which relate more closely to fuel consumption. For heightened transparency, it no longer will conduct consumption tests in the laboratory; instead they will be conducted in real driving conditions.
“That means greater transparency for the consumer and more focused climate action,” Denner says.
