From ordinary spark ignition (SI) engines the NOx is effectively removed with a three-way catalyst. This is only possible because of the low oxygen excess in the exhaust gas. Compression ignition (CI) engines and lean burn SI engines have higher efficiency than ordinary SI engines, particularly at partial load, but the excess oxygen in the exhaust gas complicates the removal of NOx. In a diesel engine optimizing the fuel conversion for minimizing NOx has the opposite effect on particulate emissions. On the other hand reducing particulate emissions during fuel conversion often means higher NOx emissions. This so-called NOx/Particulate trade off calls for a solution which involves exhaust after treatment. Alternatively a fuel which burns without particulate formation (DME) could be used at the same time as the fuel combustion is optimized with respect to reduced NOx emissions. These problems are to a high extend addressed in our research. Unregulated emissions like PAH’s, are routinely measured in our chemical laboratory. The chemical lab furthermore acts as a base for measuring the composition of fuels and lubricants and the fuel and lubricant contribution to the soluble organic fraction (SOF) of the particulate emissions.