View Full Version : Terain response?

stu bear
29th January 2009, 09:39 PM
Does anyone know EXACTLY what changes with each setting with terrain response,I constantly find here in NQ that I am on tracks that don't seem to fit in to any of the descriptions on the settings so I just leave it in standard drive setting & play it by ear.There,s nothing in the manual to say EXACTLY what changes therefore hard to make an informed decision on what setting to set it to in different situations. Is this thing just a gimick?

29th January 2009, 09:53 PM
No gimmick although it's taken some time to (A) understand what's going on and (B') to trust it.

I use the first click (Grass/gravel) 90% of the time for anything not bitumen and not specific to Sand and Rock Crawl mode, as these modes work and should be used as advertised.

Mud Ruts is a bit iffy, not because it does work, I find it's just not that simple a choice.


29th January 2009, 10:12 PM
Not exactly sure on the D3 but if it's similar to the FL2 then:

Grass/Gravel/Snow is maximum traction. Traction control and ESP are on full with gear changes quicker and throttle response dampened. The car will do what it can to not spin wheels.
Mud Ruts. The system will allow even and controlled slip of the wheels in an effort to gain traction.
Sand. The system will do what it can to keep the vehicle moving. Increased throttle response, allowing the engine to rev higher and wheels are allowed to spin more freely in an effort to maintain momentum.

29th January 2009, 10:19 PM
For me, Its all about the amount of slip that is allowed per wheel, and what response the throttle has. (imagine it does something to the ABS as well, but not certain)

Definately agree grass/gravel/snow is the way to go. Basic drive with reduced throttle input, anything that is a slippery surface where you don't want a lot of wheel spin. [in snow, i have had my foot flat on the boards and no wheel spin - very strange feeling let me tell you (is the motor still running?) - vehicle did not move - turned of DSC - all good]

Mud and Ruts, (next one around) allows a significantly higher rate of slip per wheel. (cuts throught slush on the top). increased throttle response. I still turn DSC off if attacking a hill.

Sand, totally different, lots of throttle input, immediate response to throttle input, gives you all the power its got, will spin wheels to your hearts content with DSC off, which is the way to go in sand.

Rock Crawl. I personally use this one a lot. Very soft response to throttle (going over a bump and your foot slips doesn't send you flying) centre differential locked up pretty tight, traction control kick in very early with this setting, very little slip allowed. I use this for slow work, and use this when utilising hill descent control (which I use often). This setting is for when you want the most control over the vehicle as possible.

So basically, the settings are just names. It is about understanding what impact each setting has on the way the vehicle responds to your input, and then, magic.

30th January 2009, 08:57 AM
see attached

30th January 2009, 09:35 AM
Oh boy... I can talk about this one for hours!!!

There's a whole load of systems in the D3 which are 'Tuneable'... The different programs on TR effectively tune the car to make driving on these surfaces easier. Here's a basic list of the areas TR can control:

Diffs. The differentials on the D3 are known as 'e-Diffs'. These differentials are limited slip where the pre-load can be adjusted electronically.
Gearbox (auto). TR can either hold the gearbox in gear for longer or change up sooner.
Throttle. TR will adjust the sensitivity of the throttle.
Hill Decent Control. TR will (dis)engage HDC if needed.
Suspension. Like HDC, it will change the suspension setting if needed.
Traction Control. TR will adjust when DSC kicks in. Turning off DSC doesn't actually turn it off... It just pushes it further back into the program (so you have to push it harder before it engages).

OK... There's a simplified list of what it can get up to, here's a rough idea of what it's doing in each program (note there are different settings based on if you're in Hi or Lo range):

Special Programs Off: Well... It's as it 'Says on the tin'.
Grass / Gravel / Snow: AKA 'Slippery Conditions'. The main things you'll notice are that it will make the throttle more 'progressive' and change up gear sooner. It's also the only program the system will retain if you leave it on when you park up (e.g. it's winter time & there's snow on the ground).
Mud & Ruts: Progressive throttle, suspension raised, HDC on.
Sand: Throttle very responsive, HDC off, DSC.
Rock Crawl: Only available in Lo, very progressive throttle, very sensitive diffs, holds in low gear for longer.

There is a lot to Terrain Response and I'm leaning more all the time.



30th January 2009, 10:40 AM
Every car with ESC and an off switch merely reduces its sensitivity, not disables it completely. Exceptions are some track-biased sports cars.

LR have tweaked TR over time. I don't know how exactly, but they have. I think the differences in modes are more apparent in 2008 than they were in 2004.

Best to think of TR not for specific terrains, but how you want the car to react.

For example, I find the gravel mode isn't quick enough response on the throttle, so I drive in normal or sand on dirt roads. I would use rock crawl over dry dirt where the articulation is tested and you need to go slow.

Sand mode on the D3 is fine but it can be too keen to change up, so I'd use manual gearchanges.

If in doubt just leave it in normal.

For water choose the mode suited to the underlying terrain.