[slowmover]

The first question is always:

What are the projected savings on an annual basis?

There’s a goal or there isn’t.

Thus, the first test:

1). Take to truckstop out past edge of town. Preferably 25 or more miles from cold start. Top off fuel tank to first auto shut-off.

2). Weigh vehicle on CAT Scale. Only driver plus gear kept permanently aboard (till the day it’s sold).

3). This is how tire pressure is set. Accurate numbers. Given that a cold (sat overnight) reading was done at home, use the tire manufacturer Load & Pressure Table to get CORRECT pressure value. Too much IS NOT correct for handling, steering and braking. This is truck. High COG. Don’t screw these up!

3). Take a 200-mile plus round trip via Interstate back to that same fuel pump. Refill in same manner to auto shutoff. Check tire pressure again on stopping. Should not be more than a 7% rise from adjusted cold read.

4). Engage cruise control before the end of the entrance ramp. 58/mph. Note rpm setting. . No higher. Do not cancel except to get slow passing traffic around you. At the end of the outbound run (choose a crossover WITHOUT any traffic), make your quick stop and going o the inbound portion. Don’t let it cool.

Glide on back. Avoid ALL pack formation. Watch mirrors and plan to get them around you fastest.

Ideally the brakes are used only when exiting. Same idea for manual use of throttle. Let the drivetrain do its job. You’re there to steer, primarily.

This loop will give a baseline that with by-the-book tire pressure and computer-control of speed can be easily replicated.

This number is as good as it will get. Aero is for the higher speeds of maybe 62-64/mph that commuting will keep you from being a rolling roadblock. Below the big trucks, yet they can pass you easily.

Without this basic info of what is possible one winds up where so many others do: fantasy.

— CAT Scale has a phone app. Directions of scale use on website. Go inside from diesel fuel island for your paper copy (if app PAY feature set up).

— Load & Pressure Table at tire website. Print a copy.

— This is NOT about mods in driving or the vehicle to get highest number. This is about a relaxed weekend morning drive letting things fall where they may. That anyone can replicate (no knowledge of desire for higher mpg).

From here is:

1). Annual highway miles expected.
2). Gallons consumed ($)
3). What percent savings will justify “spending to save”?

How can I make my 64-mph trip as fuel efficient as my 58-mph trip? Is the question now quantified.

(Removing roof rack just degrades utility. As does mirror change. (Thus, why own this Vehicle?).

FE is the maximization of steady-state. Until that is a given, other changes won’t pan out. IOW, I can run your truck “as delivered” at a higher highway mpg than you with your thus-far modest changes. All test parameters the same.

So what I’m trying to say is to “get the driver out of the way”. The desire for better mpg will effect the driver far more than vehicle changes at first. Will give inaccurate results.

Get the Baseline Highway MPG.

The only number that matters ISN'T the weekly out-of-pocket expense, but the annual percentage change to the Total Cost of Ownership when expressed as cents-per-mile. CPM.

The VAST majority see how low is that change to the CPM and just give up. But the more miles and years, the more important it becomes to establish new habits and to be sensitive to conditions of road, load, traffic and weather that effect an otherwise sound vehicle.

Only a beginner thinks it’s about “going slower”. There’s a great deal more to never stopping, never idling, all to maximize the Average MPH for a given vehicle.

So, find the engine hours. Compute the trucks overall average speed at present. Use that as gauge more than worry over fuel burn (as inaccuracies abound until a complete year is recorded). THIS will maximize your aero changes.

Your vehicle is better than you. Until one learns to give it exactly what it asks for (and no more), and has a baseline to work against . . .

. . the temptation to say, “oh, not today, I’m in a hurry” (HA! Sucker. The only guy who’s in a hurry didn’t plan his use well. Now will “abuse” vehicle to counter that — daily? — personal failure).

A plan based on real numbers. The willingness to acquire new habits and be disciplined about them. Safety over stunt driving. Longevity over stupid pet tricks with the drivetrain and tires. Etc.

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