The lean gasoline emissions aftertreatment project (LEAN-G) started at end of 2015 to identify possible aftertreatment solutions for lean gasoline vehicle applications. The project determines which aftertreatment solutions are suitable for lean gasoline applications, targeting three major internationial emissions legislations (WLTP, RDE, US) via a V-SIM model based simulation and predicts the fuel consumption advantage over stoichiometric engines. The aftertreatment performance assessment is run for lean stratified and homogenous gasoline C-Class vehicle applications and includes an aftertreatment cost estimation.

Customer Benefit

Lean operating gasoline engines have an advantage in fuel economy over stoichiometric gasoline engines and could contribute to future required CO2 reduction and emissions control. The simulation approach can identify technology solutions in a very cost effective way. Lean gasoline engine technology has the potential to reduce fuel consumption by over 10%, depending on the lean combustion mode and the selected aftertreatment system. The V-SIM simulation process can answer key questions of emissions control and other possible technology challenges can be identified.


The project is based around a 1.5-litre generic C-Class vehicle and simulations have been undertaken for stoichiometric, lean stratified and lean homogenous applications. Lean gasoline aftertreatment system simulated over major industry emissions cycles (WLTP, RDE, US):
• Single lean NOx trap aftertreatment system
• Twin lean NOx trap aftertreatment system
• Twin lean NOx trap in combination with a passive SCR system
• Active SCR systems


Please get in touch at innovations@ricardo.com for more information about this project.