MPG and RPM Question for Chevy truck-New RVers

I towed my old 32’ Trailer Bay for 10 years with my ‘03 1/2 ton Ford F-150...8.5 - 9.5mph. Never exceeded 55-60mph.

5 years ago I switched to the 3/4 ton diesel in my signature and it’s like night and day as far as towing. No comparison. Lots safer and more fun. I normally get 10.5 - 11.5 mpg towing. I don’t exceed 60 mph. Other towing guys sailing by at 70 mph...what’s the point?......that’s a lot of weight and mass behind the cab if things go south.