Why automated transmissions skip gears.

Can only answer on Cascadia.

In the first bit of driving the transmission/computer will teach itself your weight/terrain & adapt its shifting as it deems appropriate.

 

Two different transmissions, but the Freightliner sounds to be set up for fuel mileage.
There are a couple different shift strategies that can be used.

 

Automatics are trying to save fuel. If your truck has a setting, AND THE ECM & COMPANY allow it, put it into manual mode if it bothers you. I found I could hold the shift paddle up or down, not just press and release it, but hold it all the way up or all the way down, and that would stop skipping of gears or the early shifting into an inappropriate gear. I would use this technique when approaching a climb or during a climb so the transmission wouldn't skip into the wrong gear early and kill my momentum. Maybe that's a tanker thing and me anticipating the surge helping/hurting the transmission's flat-land shifting plan.

 

Yep, all in the programming.

 

My company has set the Mack truck in eco mode so it starts in 4th then jumps to 10, 11, 12. I’ve killed it on off ramps because it doesn’t have enough power to pull out of an inclined stop sign and I have no way to manually shift it down from 4th.

I’m sure the company has paid more for mechanics and tow trucks to pull me out of construction sites then they would have on diesel if they’d put it in normal mode or allowed me to manually shift down when required.

I get paid by the hour so I have no problem waiting on a tow/mechanic.

 

On Freightliner if loaded light no reason to go thru every gear if the engine can pull and skip a gear. They transmission can control the engine and it know if the engine can skip a gear and keep pulling. They also have a terrain mapping they claim. So the truck know how big the hill is. It also can sense the load on the truck and can skip gears when possible.

when the truck manufacturer makes the engine and transmission they can talk to each other and work as one. The first generation automatic could not and they had to go thru every gear. They also had trouble pulling hills because and would keep shifting up and down because engine could not pull the next gear.

Today’s truck like Freightliners can see the hill and know how long it is and senses the load. They it can change the shift point(rpm) depending on all that information.

 

Both my 2025 & 2026 Kenworth W990's with Easton TX-18 transmissions will skip gears as needed and often in the lower gears. On High Jake when you let off gas it sometimes drops 2+ gears as needed to slow you down. It skips more when empty or bobtail. And we do have manual mode which I use to prevent dropping gears when using medium and high jakes coming off mountain passes just holding it back not trying to stop