Why has our Nissan note 2016 dropped mpg from an average of 70 to 55 over short period of time. It has only done 46,000 and driving pattern has not changed. it’s not binding brakes, have changed fuel filter, oil filter using correct oil. EML came on due to engine computer trying to regenerate the DVF side effect excessive diesel raising the oil level.

Certainly the DPF regenerating and diluting the oil with diesel wash-down is a major cause of lower MPG
This is due to lower compression being produced as the rings are not sealing due to thinner oil
Only Low Ash oil recommended for that engine should be used but at least the diesel wash-down will have cleaned the engine internally 🙂