That is the beauty of synthetic. it will run the miles and you are protected. I am not a fan of mobil 1, but I have been using synthetic since the 70's.
All my cars are lubed with AMSOIL, and they all are on a 25,000 change interval. In the old days I used to have to change the filter at 12.500 and add a quart. They have advanced with their filters and now you can go the whole 25 k with the same filter. All my cars are keepers and I only sell them when they get to high mileage. I then look for a new low mileage jewel and start again.
Our motorhome has 20/w 50 AMSOIL Diesel oil, full synthetic and I run twice the interval as petroleum oil. I usually have to change at 6 K but with Synthetic I go 12 K.
Check out this 1996 Lincln Town car. Only 70,000 original miles, and it's filled with AMSOIL synthetic, including synthetic ATF transmission fluid.
With Synthetic you can go on our trip and forget the worry of a few miles over the limit