Is MB Re-mapping the E-550 Coupe?
Recently I had my 2012 E-550 coupe in the dealership for some warranty work. When it was finished, the service adviser told me that they had performed a software update to my car. He said the update was to allow the E-550 to run ANY grade of gasoline ???? Supposedly so many people had begun using Regular (87 Octane) that MB needed to update the mapping to avoid any "pinging". Immediately my car seemed to have less power and darn sure the MPG dropped very noticeably. And NO, I did not switch grades of gasoline. I continue using Premium. I complained to the service advisor and he said that once a flash is done - it can not be undone.
I would GREATLY appreciate the input from other members who have experienced this upgrade or who have any knowledge about it. And lastly, how can it be undone and my engine returned to its original power, performance and MPG.