Using the trucks cruise control while loaded?

Of course.
It will be largely more efficient on flat terrain, so if you're in a hilly/mountainous area of the country you'll wean yourself off of it in those situations because you're constantly dropping gears and having to hit resume. (In a manual tranny I assume).

 

YES.


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It depends on how the ecm is setup, what did your ecm dump tell you about the settings for the cruise control.

 

If my cruise doesn't work, the truck is pretty much officially broken until it's fixed. I have an ISX15.

 

It's much more efficient on flatter ground. On the roller coaster hills like Iowa or Missouri no. Because it will apply full throttle over the crest of the hill. That's a big waste.

 

Right.
That's where years of experience will help.
You'll learn your truck.. your operation.. how your lane works most efficiently with your equipment, etc.

Cruise will definitely be the most efficient use of your fuel and equipment on level, easy runs.
If you're a hard charger... a left lane gouger.. pushing the limits all the time.. May as well use the pedal.

If you're willing to stay mostly to the right, and let traffic flow past, where you get to keep your momentum flowing and not a lot of herky jerky on/off left/right lane switching you'll find benefits in the CC.

 

My foot don't like holding the pedal down all day. It also has a hard time maintaining constant speed.

Cruise all day long.

 

Latest adaptive cruise cancels quite a lot of that. Has a GPS memory of grade ascents/descents for Major US roads.

Some override or cancellation might be called for. Mainly due to traffic density or weather.

CC is PART of the computer decision-making along with gear choice and EB actuation. Your braking tactics and downgrade speed maintenance have sophisticated backup now. New strategies available.

This ain’t 1979 anymore.

Don’t assume. READ the operator manual and make a cheat sheet to tack onto visor.

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