Rear-End Gear Ratios

[Rig Wrench]

My own personal experience, my truck has 3:90s and 11r24.5 tires, I've often thought of putting 4:10s in it, or even 4:33s cause I'm consistently 100k+ in the Catskills and Adirondack mountains. About 65% 2 lane, 35% hi way. I just pull it back a few gears in the mountains and keep it 1700-1800. I do think the lower gears would take strain off the engine though. I believe on the big road it would be revving more, but not necessarily using more fuel because it wouldn't be working as hard??