Abstract
The European Commission promulgated key details of the 2019 vehicle model year emissions requirements (Euro 6d-temp) on 28-October-2016: less than two years before any new production vehicle must be fully compliant to them (new vehicles sold on or after 01-September-2018 must be compliant to these new standards). These new details (particulate number limit of 6.0 x 1011/km as part of Real Driving Emissions which may include a cold start at temperatures as low as 5 ˚C) drove major hardware changes (the addition of a gasoline particulate filter) which was previously unrequired. Given that the development of a typical vehicle program takes five years, creative and extreme engineering was required to avoid a prolonged “black-out” period in the vehicle plants, which would cause massive loss of revenue and would cripple the dealership network as they ran out of products to sell. These engineering efforts include working around packaging constraints meant to avoid major architectural changes that cannot be done in only two years. The result is an underfloor installation of the filter (instead of the preferred close-coupled installation) and a corresponding control strategy to enable the regeneration of the filter during unaggressive city driving or other common driving styles which would typically not produce enough exhaust heat and flow to oxidize the accumulated soot in the particulate filter. In conclusion, this system was put in production, keeping the program fully compliant without interruption to production.