[slowmover]

As always, addressed to anyone with an overpowered TD pickup:

6-6-6 Rule

60 mph
600F
6-psi

It doesn't mean much in practice. It's representative. Diesels like to be worked. Which is more important.

All one does is to establish habits which make for best conditions: avoidance of other traffic the priority. Safety, and economy follows. As an exemplary habit, back off to get other traffic around faster. Crowds or individuals. Thus, "managing" traffic means more than set speed rpm, MAP or EGT.

Turbodiesels are not gasoline motors. Throw out that thinking. Doesn't apply. High cylinder pressure is a different motor. Increases to vehicle weight and grade ascents don't affect them the same. Let it tell you what it wants. It will.

Drop from Overdrive to Direct as needed. Let the engine work. Percent engine load is more useful than EGT or MAP. Don't exceed 80%, as a rule. Experience will make smooth. Anticipation, how to shift (not when), how to maintain headway will come with practice.

Focused on mpg will not give results desired. You wouldn't hike that way. You'd have establish a good pace. Neither fatiguing nor apprehensive. The goal with both is to not arrive exhausted. Even tired.

It takes practice. Mindfulness you've already got. But apply it to the flow. Headway.

Fix the mechanical items. Measure those relationships (in spec). Then let it run as God and Clessie intended.

These days I'm running a smoothbore tanker. No internal baffles. 5000-gals in a 7000-gal tank. "Anticipation" is all I do. Can't stop, can't lane change and can't regain speed without an opposite (sometimes dangerous) reaction from that product sloshing around. To maintain headway I have to accept low mpg in some situations, as controlling the rig (and that liquid) is paramount. Take a page from this book: deal with traffic, terrain and weather for best outcome. Road & Load. Lane-centered and still upright. Let mpg take of itself. It will.

This rig sports a revving 12L Cummins. Not a big power 15L. I complete ten gear changes when loaded before I hit 15-mph. 250-rpm shifts. With another eight to go if I'll be running top speed. Try for some relative stasis with that fluid back there. Done badly it will literally stop me in my tracks. When to shift is "simple"enough (time according to slosh; wave periodicity and two waves at once make it interesting), but how to bring the engine back into engagement is another.

One has to have enough power at the re-engagement point to be smooth. This isn't different than with my personal rig. I'm not aimed at a particular FE rpm, but the one based on power. (The throttle exists only to move between gears).

One looks to the percentage change from loaded to empty. For this work rig it is from loaded to empty. At this stage it looks like 25% (early days). Remember that the addition or subtraction of 43,000-lbs is the only change. Your comparisons MUST be as exact to arrive at a solid baseline (once repairs and maintenance are complete).

The only thing that matters is the average (predictability), and the percentage change to that average on an annualized basis in order to decipher fuel economy. Work done well first, and cents-per-mile second.