"High mileage" oils have additives that restore rubber gaskets and seals (softens them up and causes them to swell). This can reduce or eliminate oil leaks.
BMW, Mercedes-Benz, and VW Group (VW, Audi, Porsche, Bentley, Lamborghini) use synthetic "super oils."
Various 5W-40 and 0W-40 synthetic oils meet BMW's Long Life 01 (BMW LL-01) specification. Back when your car/truck was built, BMW required an oil that met ACEA A3/B3 oil. ACEA spec's are European, and not all synthetic oils sold in the US meet them. The BMW LL-01 spec' exceeds ACEA A3/B3.
The BMW (branded) 5W-30 that meets BMW LL-01 is actually "thicker' than most 5W-30s, and its "almost" a 5W-40. But, there are cheaper BMW LL-01 certified oils made by Castrol and Shell (sold under their Pennzoil and Quaker State brands in the US).
Burning one quart or liter of oil in 7500 miles with a turbocharged engine with 125k miles on it isn't bad. It's probably better than average. Also, the electronic oil level measurement becomes less accurate with time. Your actual oil consumption might be less. The only way to really know what your oil consumption is is to do you own oil changes and measure what you drain out.
I recently changed the oil in my 2014 535i with the N55 engine. The car has 78k miles in it. It burned about one liter in about 6900 miles. That's higher oil consumption (less mileage) than previous oil changes. But, my last oil change was done at the dealer while they were doing other work. So, they might have short-filled it by a quarter liter or so. I need to do two DIY oil changes in a row to have an accurate measurement of oil consumption.
Do a website search for "LL-01." The resident oil expert here is "edycol." He works in the industry. Listen to what he says, and question anything anybody else says that contradicts him.