I believe it is ideal for oil pressure. I have read this before and have also spoken to others in the car industry. The min tells you that you are going to drop below safe levels and the max tells you that you have too much oil. It is at mid-level where engine oil pressure is ideal. From min to max is 1 to 1.5 liters depending on the car so while there is an effect on pressure and consistent pressure levels. Now if you're burning oil, you probably want to add to the max to avoid having to top off too often and the potential of dropping below the minimum. Usually when I change the oil on my Rover the digital dipstick reflects "max" which I'm fine with. It doesn't really burn much oil but on my last oil change which I did at about 4,500 miles, the dipstick was at mid-level reflecting some loss. My e39 and e46 BMW's I maintain at mid-level which I feel is easier to do with an actual dipstick and where I feel the engine feels right. In the end, as long as you are between the min and max, you are safe. Checking oil levels often is easy and worth it.