While in Phoenix over the winter I stopped at a Ford dealer for an oil change on my F150 Ecoboost. During check out, after the 90 minute job, they mumbled that I was due for a Brake System Flush, a Fu...
Follow the schedule in your owner's manual for a vehicle in heavy service (if there is a different schedule) since you are towing.
If there is not a heavy service schedule, and you tow very much, do the tranny fluid flush at 2x the recommended intervals. Do the other things at recommended intervals.
Run some Seafoam through the fuel system about 2X/yr.
Don't believe what the dealer service departments try to sell you.