96 hours, including two five hour drives.
Spent an entire three days in Philly several years ago awake, made it to four full days with the 10 hours of driving and the time awake both before leaving and after getting home but before going to bed. After driving home, slept for almost two full days, with breaks only to acquire beverages and then void said beverages several hours later.
Oh, and caffeine makes you
not
, at least it does to me.