Premium Grade Fuel or Not?

What credentials does the referenced writer have. It has been my experience that many newspapers quote most anyone as an authority. The information quoted would have been OK some years ago, but today when they say required, I believe the mean it. If it is your car, go ahead. I will stick with the requirements that the guys who make their money designing engines rather than the guy behind a keyboard at the news paper, who might be reporting on what color short to wear next week.

Who do you consider the most knowledgable people on what you should be using in your car, the author of the newspaper article or the engineers who designed, tested, and did the reliability engineering and testing on it?

You are free to believe either. Personally, I’d have more faith in what BMW says.

he only relevant question is whether or not the car can be safely run on 87 octane fuel.

No.   There is also the question of performance and mileage, both of which can suffer on a car that was designed for premium. 

It does seem foolish to pay for a performance car only to dumb it down by cheeping out on the fuel.

Your second point is really important. It seems to me that most of the people who try to cheap out on gas never think about the cost per mile, just the cost per gallon. On a cost per mile basis, risking engine damage makes even less sense.