We just bought a 2017 F350 Diesel in preparation for moving from Washington to Arizona late next week. While I will be driving a 42' motorhome towing a car, my wife will be driving the F350 towing a loaded 8.5' x 20' - 10K cargo trailer and I need to explain to her how to properly use the engine brake feature while descending mountain grades. I will have no opportunity to try this out myself before we leave, so it is important I prepare her properly before we hit the road. From what I glean from the owners manual, the Automatic selection sounds less complicated than the Manual. But I am still not clear how to explain the variables. I get how to set the speed, i.e. last input from the accelerator or the brake as you start down. But what about changing speeds on the way down, like braking to take a sharp curve, then wanting to returning to the previous descent speed. Do you just brake, take the curve, then that is your new set speed until you accelerate to the previous speed and release the throttle? If you coast (without accelerator) up to the previous speed, do you tap the brake to set the desired speed? Ford didn't do a great job explaining all this.

Any thoughts on how to educate her and make this a safe experience would be appreciated.

 

Whenever you brake, that becomes the new speed setting. After a curve, etc. accelerate to the desired speed and set the brake again.
You won’t be able to coast up to the previous speed, it will require throttle input to increase speed.
Manual engine brake is very easy. Simply turn it on. If you don’t accelerate, the truck will continue to slow until accelerator is applied. Let off the pedal and it will begin to slow again.
I once set the auto brake and then pressed cruise to see what would happen. It seemed to work pretty well until I slowed, which turned off the cruise and set the brake for a new lower value.
In any event, there is nothing inherently dangerous with the engine brake. Far more aggravating is if you forget to deactivate cruise and start down a mountain. The truck will drop into 3rd gear and ver nearly red line. It won’t disengage third until you accelerate, even if you turn the cruise off.

 

I think it would be simpler to tell her to set tow/haul and the regular exhaust brake. It will have some quirks, but nothing that will br a problem.
I have tried the Auto function and it's not a lot different

 

There is a quirk with tow/haul and engine braking that may come up. When descending and the truck goes into 3rd gear, it may seem very reluctant to shift up out of 3rd gear. It may require a significant amount of RPM increase to make it shift. What I do instead is change the gear shifter to M (for Manual) mode and then I use the +/- buttons to force a shift to 4th gear. Then I can move the shifter back to regular D mode.

It may be possible to just wait it out by letting the truck slow more than you would normally let it at the bottom of the hill.

Otherwise, keep it simple and hammer the accelerator until it does shift up.

 

I click it once. I think there is another setting you are referring to, maybe that is for steep grades.

Anyway, I am going to add that tapping the brake quickly will start it to downshift and engine brake early. I am not a big brake pedal rider even with a lot of weight in tow but I like to communicate so it stays alert.

I only tow in downtown Houston traffic on the freeways. Click the exhaust brake button once and put in tow haul. If I need to merge I swerve at people and vice versa.

Only one highway trip, 50 miles trailering at consistent highway speeds and I do not like the lighter steering in tow haul mode but its not scary. I think only trucks with adaptive steering change the sensitivity in tow haul. If she turns it off because of this I recommend turning tow haul back on if you get into grades so the computer knows whats going on.

 

Adaptive Steering only functions at low speeds.

 

Felt different to me.


Guess its something you would need to get use to. I clicked it off and on. May or may not like it. I guess it stabilizes the truck some incase of bump steer?

 

If the adaptive steering was active at highway speeds like it is at lwo speeds, you would be in the ditch while trying to change lanes. However, you're right in the sensitivity. At higher speeds, adaptive steering reduces sensitivity when the tow/haul button on.

 

Yeah its different. May be a safety thing incase of bump steer, etc.

 

Thanks for replies. I am learning here.

Let me ask this. Is there an actual intake or exhaust restriction component to this engine braking feature like you see in a Jake or PAC brake, or is it all transmission control in a SD diesel?

Ps. I do not have adaptive steering.

 

The exhaust brake is done with the vanes in the turbo.

 

Should run the truck for a 1000 miles before towing. I would get your wife some wheel time in that spell, use tow/haul, know how to manually shift down with the plus minus, know how to drive in manual mode, understand and know locations of the cruise buttons, mirrors etc etc. It doesn’t take long to get used to where everything is but towing 10,000 lbs does require some experience. Once you know what the truck can do, will do in certain circumstances, it’s a lot more comfortable driving towing a load.

 

what concerns me here is no mention of adjusting the trailer brake controller which I would think is more important than trying to use the truck to do 100% of the braking via the engine brake.


would suggest you post over on one of the trailer sub forums and get their input.

 

I appreciate your thoughts but I think you missed the part about leaving Washington for Arizona next week and we have no significant hills nearby to make practice runs. She has a lot of previous experience hauling horses around the western states so driving skills while towing are not of concern here. And she has already familiarized herself with the normal features of the truck. It is just the Engine Braking feature in actual use that prompts me to see if I can give her some useful information to employ the feature safely and efficiently.

And speakerfritz, let me alleviate your brake controller concerns. Once the trailer is loaded, we will make a practice run and set up the controller before we start out on the trip. We are definitely not ignoring the brakes.

 

Deleting duplicate post.