Virtually all carmakers use particulate filters in their diesel cars to meet the most stringent emissions standards. These filters trap particulate matter left over from the combustion process that can be harmful if inhaled by humans.
Gasoline-powered cars generally produce lower levels of particulate-matter emissions than their diesel counterparts, and thus haven’t been equipped with filters. But Mercedes-Benz believes fitting gasoline cars with the particulate filters from its diesel cars could help meet stricter future emissions standards.
The German carmaker says it is planning “large-scale use” particulate filters in gasoline-powered cars, and claims to be the first company to make this move. Positive results from field testing on the S 500 sedan led to the decision to fit production gasoline cars with the filters, a Mercedes statement said.
The S 500 is a European-spec model; Mercedes instead offers the similar S 550 here in the U.S. Gasoline S-Class models will be the first to get the new emissions-control equipment, as part of an upcoming refresh. Mercedes says it will then add filters to other models as they are refreshed and redesigned, or as new engines are added to the lineup.
The company did not release a timeline for the addition of particulate filters, or specify whether the modification would apply to cars in all markets or just Europe.
The announcement was made in concert with the launch of a new modular family of diesel engines built to comply with stricter European Union “Euro 6b” emissions standards set to go into effect in September 2017.
The first example of this new engine family is a four-cylinder unit code-named OM 654, debuting in the E 220d mid-size sedan. Other related engines will eventually be deployed across Mercedes’s car and van lineups.
The announcements come as Mercedes and parent Daimler face increased scrutiny as a result of the Volkswagen emissions scandal. In February, the EPA asked Daimler for additional information on emissions testing in the wake of a lawsuit filed by owners alleging inaccurate emissions figures for a 3.0-liter V6 engine.
In April, a second lawsuit was filed. Like the first, it claimed laboratory test results for the 3.0-liter V6 didn’t match real-world results. Sales of the 2017 Mercedes GLS 350d SUV are currently on hold, pending final EPA certification.