This is an aftermarket turbo. The MB's equipped with turbos have been modified as necessary to provide adequate durability under turbocharged operating conditions. None of the four cylinders have ever had these modifications at the factory.

I would expect the life expectancy of this engine, if driven aggressively, would be measured in a two digit number of hours. Since the car is for sale, it could be that this number of hours has already passed.

Have a great day,