Are you serious? If you have driven the car for 7 years and 80,000 miles you have nothing to worry about. They add turbos to non turbo engines all the time and unless you are racing or hauling heavy loads it has practically no effect on engine life. If you baby the car and maintain it by the book, the engine is in no danger and you don't need to change anything.

So stop worrying and enjoy your Benz, you have nothing to worry about.