No, it is not a secret.

Many BMWs use some oil. I typically add a litre every 8000 km (5000 miles). It likely has some relation to break-in practices, but that is hard to prove. Back when we all did oil changes every 3000 miles, 25 years ago, it wasn't as much of an issue. One quart between oil changes wasn't unusual, and it was why gas stations sold oil. With up to 15,000 miles between changes now, it is natural that occasionally some oil will have to be added. My dealer provides top-up oil in my trunk, in a BMW case with a funnel and gloves.

BMW has, I believe, a policy that consumption up to and including one quart every 1000 miles is 'acceptable'. I would agree with you that it wouldn't feel very acceptable to me, but that is the published policy. Now, before you rant at BMW, know that when I worked at a Ford dealer, it was the same consumption (1 quart/1000 miles) before they would open up the engine. They used the diary forms as well. The 1000 miles isn't only a BMW figure, it is more of an industry cut-off point. Yes, it seems like a lot. Do a search on oil consumption, and see how many threads are on here about it. So no, it isn't a secret.

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