Engine braking on 2017 F150 5.0L

mkirsch wrote:

Turtle n Peeps wrote:
Modern computer controlled trucks do not over rev. It's impossible because of the computer.

Anybody that is worried about over reving their "modern" truck is worrying about nothing. They need to go a rev anonymous meeting. They are held at their local race track. I haven't been to any in a long time but when I did I took my 572 to 7,000 RPM time after time. And this thing has pistons as big as a small coffee can.

Let it rev.

That's true when you're stomping on the go pedal, but is it when you are being pushed down a grade by a big trailer with your foot off the gas?

When you're being pushed you can cut the ignition all you want and it's not going to limit anything. The only thing that will bring RPMs down is an upshift, and I don't know of anyone who has let their rig go that far to see what would happen.

For science, I've let my 8.1L/Allison go to 5000 before I hit the brakes, and there was no indication of it upshifting or doing anything but dropping another gear in a futile attempt to maintain speed by engine alone.

You may be right. Late 02, maybe for 03 models, a grade braking algorithm was added to the Alli’s brain.
It would overrride the grade braking at 5000rpms on the 8.1 and 4800rpms on the 6.6 and command an up shift if rpms climbed beyond those points.
However it would never try to downshift again at “redline” rpms.

While the Alli 1000 was really the pioneer for “smart” transmissions in light duty trucks, it still required or requires the operator to have a little common sense and act accordingly.
Newer vehciles and transmissions are even smarter and more refined, taking away a bit more necessity that the operators have some active gray matter floating between their ears, but at the end of the day, if you’re literally adventurous enough or ignorant enough to test how well the engineers idiot proofed your transmission, you might be left on the side of the road somewhere. Either rubber side down if you finally decided to use the service brakes soon enough or rubber side up if ya continued to tempt fate until it actually answered your call! Lol

Now, recent models with adaptive cruise and active collision avoidance/auto braking, have taken it one step further before fate comes knocking. But like any mechanical item, someone somewhere is bound to be ignorant enough to break it by not braking it….