SOURCE

When buying the car, the bolt on the DMRV was tightened by 13mm and nobody had touched it since then. I didn't get to fully enjoy this configuration as the car immediately went off to an electrician for precise ignition adjustment after starting the engine. I don't know what guided the electrician but he tightened the bolt another 0.7mm. In this configuration, winter fuel consumption was 12.5l/100km.

If you look closely, there are numbers next to the bolt and if you convert them to mm, it becomes clear that according to factory settings, the bolt should be recessed by 12.3mm instead of 13.7mm. By loosening the bolt back to its factory position and measuring fuel consumption, we got 12.2l/100km.

Location of the bolt and numbers