djb

if you do, keep track on pre tour test rides of pressures. I found that you don't need to have too high pressures to get really good rolling resistance. The psi obviously depends on total bike weight, so dependant on everyones diff situation. On my long trips, it gave me something to do, to try different pressures, and to adjust in small amounts and go by feel. Spending all day on a bike day after day after week gave me lots of opportunities to try out diff pressures, and often would just "burp" out a bit, just to take out the overly harshness, and still had good rolling.
If attentive, you quickly get attuned to what is that psi that is good for comfort, yet still rolls well.
I sometimes adjusted for road surfaces, and going just a bit lower often made a huge difference for my comfort on rough or loose stuff, well worth it for the days worth of feeling tired and less beat up.

Less beat up = less tired = more energy over the day = faster overall