I ran an incredible and steep trail this weekend in the Sierras, which descends from 10,400 to 4,200’ via tight offroad switchbacks in about 5 miles or so.

At the top, I engaged hill descent control. Very comfortable cruise. About 40% of the way down, I began to smell the brakes overheating, so I stopped to let them cool. I have the V8 with the brembo brakes.

After that point, I switched to low range instead to control my downhill speed in order to spare the brakes.

My question: is HDC only designed for short descents? Is it preferable to use lo range for such a severe and lengthy descent, or will this damage the transfer case?

Thanks for your input.

 

I’ve also noticed the excessive brake usage in HDC. Generally when I am doing a lot of steep grade work off road I use low range and disable HDC and make use of the manual shifting to hold lower gears as needed.

It seems like switching to low range makes the computer much more off-road friendly as well with things like throttle response and more being remapped. Someone here can probably chime in with all that is modified or disabled when you go into low but it seems like a noticeable switch overall to me.

 

Interesting question. Similarly, I haven’t dug into how the cruise control works to slow, brakes or engine/trans control but wondered about it just the other day. We recently did the downhill west side of Wolf Creek Pass twice (still looking for C. W. McCall), and I set cruise control virtually the entire way down with multiple grade runs of 7%. I thumbed the rocker switch to slow down and speed up. I wasn’t convinced it only slows with brakes; I never did smell brakes. Likewise, I’ve run it several times in my Ford Super Duty on cruise control. I know that slows through engine control.

 

LonRange is the ticket. It gives you oodles more control on ascent and descent and I use it lots.

You’ve got 8 gears so there is no downside to using it when your in slow and/or technical tracks.

Use it to your advantage and take the pressure off brakes that ideally should be minimally used on trail.

HDC and ATPC with Lo range is great too.

It’s like using a scalpel rather than a scythe.

Find a reason to not use Lo rather than a reason to use it and you’ll have more fun on the trails.

 

I'm not a fan of HDC even though it is much better than early versions. The control you get with low range, manually shifting the gears and only employing brakes when needed has always been my preferred way to descend steep mountain passes or even short descents

 

HDC only uses the brakes, but it certainly helps to be in low range. HDC is best to be used on short hills and descents, and it is excellent at that, but you get so much more control in low range. Short descents in low range in combination with HDC and you're set.

I'm still a huge fan of HDC, though. It was invented by Land Rover in cooperation with Bosch, and introduced on the facelift for first generation Freelander in 2002. If I'm on trails with a lot of frequent small hills, I always have HDC activated.

On a side note, I'll never forget how scared my ex girlfriend was when I pointed my old LR4 down a ravine and lifted my feet off the pedals. She thought we were going to crash at the bottom and the look on her face was priceless. I then told her that her Tiguan also had HDC and she literally did not care lol.

 

Low range is your best friend when facing long descents versus HDC. Low range will use engine braking whereas HDC will activate the brakes. HDC is really hard on the brakes which is why you smelled the brakes. Good thing you stopped to let them cool down. HDC is good on short hills only and not long ones.

 

Fun fact. HDC first hit the US market on the Discovery 2 in the 1999 model year, but the Freelander actually predated the D2 in Europe in 1997, so you are correct, it was developed for the Freelander. What is interesting is -- it was developed for the Freelander because the Freelander (aside from being a piece of utter hot brand devolving garbage) did not have low range to help keep the speed down. So -- yep. Put your Defender in Low Range.. it'll save your brakes. HDC uses the brakes like crazy.

I have never reached a point where I've smelled my brakes in the L663 (yet). Good to know though.

 

Love that! When I was learning to drive, my dad had a LR3. I learned how to drive off-road at 14, and on a steep downhill on Bald Mountain in CA he pressed the HDC button and told me to let off the brakes. Scared me but I learned to love HDC. Especially after long days, its nice to give your feet a small rest. Now ofc any time I bring a new person off-road I take them to Hollister Hills SRVA and have them go down the steep up and down hill similar to those at the Land Rover Experiences. Instead of being all nice and friendly, I press the HDC button and aggressively say "off the brakes! Off the brakes!" When they do the HDC shutters the brakes which scare them even more! I do use HDC in the D2, when my ABS works, and regularly use it on the LR3. Has anyone had experience using HDC in a LR3 compared to a new Defender?

 

The issue I have with HDC for off road driving in the mountains is that I am going quite slow. There isn’t a lot of airflow over the brakes and they will get quite hot… in addition even in low range with out manually shifting and holding a lower gear it will make insufficient use of the engine braking. Which will lead to over heating of the brakes for certain. just like I wouldn’t ride the brakes down a mountain pass I certainly wouldn’t do the same thing off road with even less air cooling things off.

That all said there are a couple issues which HDC will do better than manual control pretty much every time. These are in loose are low traction conditions. The first and most dangerous—too low of a gear and too much engine braking. Sliding a four wheel drive down a steep grade without the ability to let off the brakes and regain control is a white knuckle experience. The fix for this would be a bit more accelerator but I guarantee the HDC will do better than any driver with the individual wheel control it has. The second one is probably what HDC was really made for, urban snowy conditions and shorter hills or driveways, works like magic. The duty cycle is fairly low and it’s going to be cold out so no issues over working the brakes.

As in all things it depends and skill and experience is needed to understand what to do. The fact that this discussion is happening here certainly means this little audience pays more attention to what they are doing than most and are perhaps more thoughtful about how to approach situations and can be better informed before they find themselves in a bad spot.