Do I need/want Hill Descent Control?

FirstAscent · January 20, 2020

Hey everyone, so I recently placed an order for a 3500 high country duramax and did not choose the z71 package which includes hill descent control. Apparently you can only get it with the z71 pkg.

In order to choose that package I would have to remove the interior convenience package which has the all weather floor liners and rear under seat storage I wanted.

Does anyone have this feature that thinks it’s amazing or anyone not have it and wish they did?

Just want to make sure before it’s too late to make changes to my order

AT4 HD Ron · January 20, 2020

I have an AT4, so it has it but I see no real purpose to it. The DMax has engine braking, then just use the truck brakes as necessary to slow down going down a hill. You'll be fine with what you ordered!

SilveradoX2 · January 20, 2020

2 hours ago, AT4 HD Ron said:

I have an AT4, so it has it but I see no real purpose to it. The DMax has engine braking, then just use the truck brakes as necessary to slow down going down a hill. You'll be fine with what you ordered!

Engine Grade Braking is for going downhill on highways, works in conjunction with cruise control and the Exhaust Brake. I've read use Tow/Haul mode button to amplify Engine Grade Braking. Hill Descent Control is designed for rough country downhills at slow speeds. Therefore on AT4s and Z71s. From GMC:

Hill Descent Control

Uses antilock braking to help provide a smooth, controlled descent in rough terrain
Activates by pushing a button on the instrument panel
Works without the driver pressing the brake pedal

newdude · January 20, 2020

13 hours ago, FirstAscent said:

Hey everyone, so I recently placed an order for a 3500 high country duramax and did not choose the z71 package which includes hill descent control. Apparently you can only get it with the z71 pkg.

In order to choose that package I would have to remove the interior convenience package which has the all weather floor liners and rear under seat storage I wanted.

Does anyone have this feature that thinks it’s amazing or anyone not have it and wish they did?

Just want to make sure before it’s too late to make changes to my order

You aren't missing anything really unless you drive down some steep a$$ offroad trails or something. Hill descent control only works at 14mph or less.

SkidooSteve12 · January 20, 2020

Funny that this topic came up as I was just thinking about that Hill Decent control option Saturday as we were out on some snow covered two-tracks and went down a couple of hills and I almost tried it out, but just used the brakes instead. I'm not really sure when I would use it.

On a side note, I wanted the Z71 package because of the skid plates and off-road suspension. I had to add the full all weather rubber floor liners myself and keep the floor mats on top of that as they contain melting snow and mud. And then I removed the rear under seat storage organizer because it was too small to hold everything I transferred over from my previous truck.

FirstAscent · January 20, 2020

This will be my first diesel so I wasn't sure of the differences yet on the Exhaust Brake vs other similar features, thanks for the info!

I did come across Engine Grade Braking the other day as well, anyone know if that is standard? I've never seen it mentioned or an option in the build process or in the spec. I've only seen the Exhaust Brake and Hill Descent Control.

@AT4 HD Ron I think I agree, doesn't sound like it's an option I just can't do without and worth the hassle of changing all the current options around just to add this. I've owned trucks the last 11 years and for my use I don't see myself needing that.

FirstAscent · January 20, 2020

4 minutes ago, SkidooSteve12 said:

Funny that this topic came up as I was just thinking about that Hill Decent control option Saturday as we were out on some snow covered two-tracks and went down a couple of hills and I almost tried it out, but just used the brakes instead. I'm not really sure when I would use it.

On a side note, I wanted the Z71 package because of the skid plates and off-road suspension. I had to add the full all weather rubber floor liners myself and keep the floor mats on top of that as they contain melting snow and mud. And then I removed the rear under seat storage organizer because it was too small to hold everything I transferred over from my previous truck.

You posted this just as I was posting my last post. Yeah that's kind of what I was thinking too, I lived in Fairbanks, Alaska for 5 years and drove all around the state all year round having fun and I've always done just fine or never felt the need for this feature. If I were maybe doing more off-road on steep terrain I could see it being a nice convenience, but since I'm rarely in these situations, I don't think I'll need it for the one time a year it "may" come in handy.

Good point about the off-road suspension and skid plates though, I did consider it for that however I'll eventually doing a small lift once BDS releases something around 3" or so and they always include their own style skid plate, and I'll be having Icon make me some shocks. But if I weren't going to do that, I'd want the Z71 package just for the rest of it.

Since you have the Z71 package, do you know what exactly is different about the suspension, I'm guessing different shocks? I haven't seen anything posted yet for these trucks.

SkidooSteve12 · January 20, 2020

8 minutes ago, FirstAscent said:

You posted this just as I was posting my last post. Yeah that's kind of what I was thinking too, I lived in Fairbanks, Alaska for 5 years and drove all around the state all year round having fun and I've always done just fine or never felt the need for this feature. If I were maybe doing more off-road on steep terrain I could see it being a nice convenience, but since I'm rarely in these situations, I don't think I'll need it for the one time a year it "may" come in handy.

Good point about the off-road suspension and skid plates though, I did consider it for that however I'll eventually doing a small lift once BDS releases something around 3" or so and they always include their own style skid plate, and I'll be having Icon make me some shocks. But if I weren't going to do that, I'd want the Z71 package just for the rest of it.

Since you have the Z71 package, do you know what exactly is different about the suspension, I'm guessing different shocks? I haven't seen anything posted yet for these trucks.

Reading a little about the Hill Descent mode, it says it uses the anti-lock brake system to control your descent.... but the driver can do the exact same thing? I would want to control the brakes myself as sometimes you want to slow down faster before a bump or drop off.

Not a lot that I've found for Z71 specs except this and the GM Build Specs. This is an old article anyways and odd it says the Z71 option is only for LT trim trucks? It does mention the Z71 gets a 33.6mm front stabilizer bar, which I can only assume is larger than what the other trucks get.

https://www.theengineblock.com/2020-silverado-hd-z71-an-off-road-chevy-for-heavyweights/

Another thing I forgot about, and didn't read about yet, is the Off-road transmission mode selection. It is on the same knob as the Trailer Tow/Haul mode. I accidentally selected that before when trying to turn off the Tow/Haul mode the first time I used it. I've never tried that feature yet either. But should.

The shock package description just says "specially-tuned off-road suspension and off-road tuned twin tube shocks". I just know that my previous truck was the standard 4X4 version and my dad's similar truck was the Z71 package and I liked how his truck rode just a little bit better.

FirstAscent · January 20, 2020

I hadn't seen that article before, that was a little helpful but yes I think a little outdated or partially inaccurate. At least according to the chevy builds it definitely allows me to select the Z71 package on the High Country if I wanted to add it.

Interesting about the transmission mode knob, so you get an extra option there too, good to know. On all the 2500/3500's I've test drove so far they all had only 2 options, Normal and Tow/Haul mode.

cdh7917 · January 20, 2020

Initially, I thought it wouldn't be something I would use. And it's probably something I will hardly ever use.

But, a couple weeks ago I had the chance to use it and it was handy to have.

We were returning from snowboarding and got stuck in lovely Colorado traffic on Loveland Pass. Going up the pass, no big deal - just crawl along and stop as needed. Coming down the pass I didn't want to use the brakes much if I could avoid it. I dropped the gear shifter to L1, turned on the exhaust brake, and activated Hill Descent Control.

The results were great. The truck crawled downhill, and I only had to apply the brakes when it was time to fully stop.

Can't express how badly the traffic in Colorado over-utilizes the out-dated and under-rated infrastructure. While I wouldn't have made it a point to get Hill Descent Control, it came with the AT4 package. Might as well use it...

FirstAscent · January 20, 2020

1 hour ago, cdh7917 said:

Initially, I thought it wouldn't be something I would use. And it's probably something I will hardly ever use.

But, a couple weeks ago I had the chance to use it and it was handy to have.

We were returning from snowboarding and got stuck in lovely Colorado traffic on Loveland Pass. Going up the pass, no big deal - just crawl along and stop as needed. Coming down the pass I didn't want to use the brakes much if I could avoid it. I dropped the gear shifter to L1, turned on the exhaust brake, and activated Hill Descent Control.

The results were great. The truck crawled downhill, and I only had to apply the brakes when it was time to fully stop.

Can't express how badly the traffic in Colorado over-utilizes the out-dated and under-rated infrastructure. While I wouldn't have made it a point to get Hill Descent Control, it came with the AT4 package. Might as well use it...

Thanks for your input! I snowboard here in Oregon at Mt. Hood quite a bit and I could see that as a convenience coming down the mountain pass on those extra snowy days where you're basically maintaining speed and not speeding then slowing for every straight or corner

joelabq · January 21, 2020

The z71 comes with all weather mats with z71 branding... Just FYI.

Sent from my LG-H932 using Tapatalk

SkidooSteve12 · January 21, 2020

20 hours ago, FirstAscent said:

This will be my first diesel so I wasn't sure of the differences yet on the Exhaust Brake vs other similar features, thanks for the info!

I did come across Engine Grade Braking the other day as well, anyone know if that is standard? I've never seen it mentioned or an option in the build process or in the spec. I've only seen the Exhaust Brake and Hill Descent Control.

@AT4 HD Ron I think I agree, doesn't sound like it's an option I just can't do without and worth the hassle of changing all the current options around just to add this. I've owned trucks the last 11 years and for my use I don't see myself needing that.

I think the Engine Grade Braking only works when the Tow/Haul mode is turned on? I would imagine that's a standard feature with the Tow/Haul option.

And from what I've been told when riding in a diesel truck a few times in the winter, you have to be careful when to use the Exhaust Brake because it can make the rear end basically act like you are hitting the brakes too hard and too fast and make you loose traction and control. Do some research on Exhaust brakes on winter roads, as I'm no diesel truck expert but thought that's what I was told and this will be your first diesel.

TripDad · January 21, 2020

Hill descent control work on steep low traction environments often found off pavement. It is useful but also cumbersome at times. IMO, this is like most other driver aids, a more skilled, attentive drive likely will not need them often.

L86 All Terrain · January 21, 2020

If you are into offroading in slippery environment and go down steep hills, you have probably already pulled your ABS fuse. Being able to lock your brakes up in offroad situations can be handy. Your tires will push and pile up mud or snow helping you stop in situations where ABS will just panic and send you sliding (rolling) down the hill. ABS is a life saver on icy roads, but can also be a killer offroad.