WWII bomber escort range question

I'm in a heated discussion with a friend. All the books I've read state that P-47s and P-38s could only escort bombers to the coastline of Germany. If I do the math, it's obvious in case of the P-47, but the P-38 had a very long range on paper. How come they also had to turn back and didn't escort the bombers deep into Germany?

Any docs and sources would be appreciated. Thanks!

Don't forget that part of that fuel consumption equation is the time spent at Mil power while engaged in combat. The P-38 had almost twice the fuel consumption plus almost twice the weight of it's single engine counter parts.

as you can see, they don't all start from the same place. they're also tasked with an important leg of the escort that you probably didn't have in mind.

impact vol. 2 no. 3, march 1944

apologies for the poor quality of the scan, the text near the crease reads "diversionary sweep by two squadrons of british typhoons to assist final withdrawal of bombers"