Typically three liters for a 2 hour ride (single track) in florida and about the same for a two and a half to three hour in the SE Mountains during the hot months. I sometimes run out with a few miles to go.
About half that in the colder months. The water is spiked with about 1/4 teaspoon salt per liter for the hot months and less than half that for the colder months.
I eat about 400 calories of fast burn carbs during a ride.
I do another 4 or 5 hundred calories during the half-hour window after the ride. I'm ofter riding during my normal lunch period, so I definitely need the food. I'll eat a big breakfast about 4 hours before riding with a light snack a few hours before.
Al