I did over 3000 miles in 4 days a few years back.

 

Most I would say was recent for me driving an F350 power stroke towing a 53ft trailer for work related reasons, from Chicago, IL to Naples, FL and back 3000 miles give or take, then the same week from Chicago to LA Cali and back to Chicago was a good 4000 miles round trip, total would be about 7000 miles in a week (actually 8 days total but close enough)

Redbulls, cigs, gum and a jaw breaker kept me awake