XC60 - Need information on AWD

[NigelDay]

Originally Posted by Tannaton

All Volvo's with traction control have a disable DSTC (or more specifically "Spin Control") function. On earlier models (like P1 XC90) it is a button on the dash, on later models (like XC60) it's inconveniently in a menu but this disables the mechanism for the traction control to override the commanded throttle - i.e. for use on viscous surfaces like sand and mud. Applies equally to 2WD and AWD cars.

Does the LR Disco Sport have 'basically' the same Haldex system as the XC60 / 90 ? If so, it should be possible to provide the same drive options for different surfaces as on the LR.

[Tannaton]

Originally Posted by NigelDay

Does the LR Disco Sport have 'basically' the same Haldex system as the XC60 / 90 ? If so, it should be possible to provide the same drive options for different surfaces as on the LR.

Not sure really, I did test drive a Disco Sport about 2 years ago and the promptly ordered an XC60.....

I think mechanically they are similar, the various “modes” are just software.

[JJJ]

Thanks for the response, Tannaton.

Yes, the Freelander 2, Evoque, Discovery Sport and Jaguar E-Pace has a similar drive-train layout.

In terms of suspension, the Discovery Sport has the Jaguar rear setup, but the front is essentially the same across all models.

The early Freelanders had a Haldex 3, but when the Evoque was launched, that, as well as subsequent Freelanders were upgraded to a Haldex 4 - or Borg-Warner 4, as they call it these days. This is what is in the previous generation XC60 as well. There is already a "5" version available.

The one thing I find somewhat disappointing, is that Ford did not implement the same modes for the Volvo as for the Land Rovers. It is almost as if they deliberately wanted to create two different markets, being more fond of the LR brand.

And yes, the offroad modes play with permutations of throttle response, the gear it pulls off in, shifting points and the amount of wheel spin permitted. In Sand mode e.g., it redlines the engine in every gear before shifting up, and can spin almost limitless. As for the Volvo, the DSC and HDC can be disabled. Also, when you select any of the special modes, the Haldex remains activated all the time.

Even pulling off in Standard mode, the Haldex is enabled until 40km/h, before switching to (mostly) front wheel drive.

What I would have liked to see on the Volvo was at least an "offroad" button which ensured that it remains 4-wheel drive, regardless.

The new XC40 has an offroad mode, but disables this as soon as the speed exceeds 40km/h. Volvo is thinking too much on behalf of their clients, as this would be fine for a packed surface covered in snow, but not optimal for loose sand driving.

Due to the above differences I am gathering information to see if I could go the same places the Freelander 2 has taken me. It will not be able to do so in standard form, but e.g. the excessive front overhang could be improved by a 20mm lift, or possibly modifying a used front bumper skin so the chin picks up.

It will definitely need a decent sump-guard to replace the standard one.

As I've worked through the offroad related posts on this forum, I noticed the European application/expectation/motivation for buying an XC60 is very different to the local one in SA, and the AWD is more regarded as a safety feature in poor weather, northside. Also fuel economy seems to be very important, so most buyers go for diesel.

[Tannaton]

Originally Posted by JJJ

Thanks for the response, Tannaton.

The early Freelanders had a Haldex 3, but when the Evoque was launched, that, as well as subsequent Freelanders were upgraded to a Haldex 4 - or Borg-Warner 4, as they call it these days. This is what is in the previous generation XC60 as well. There is already a "5" version available.

Borg Warner acquired the "traction" side of Haldex in 2011 and are gradually phasing the brand name over to their own.

Originally Posted by JJJ

The one thing I find somewhat disappointing, is that Ford did not implement the same modes for the Volvo as for the Land Rovers. It is almost as if they deliberately wanted to create two different markets, being more fond of the LR brand.

The motor industry is littered with "badge engineering" for revenue protection. VW are the masters of it, it's why Passat interiors are slightly "low-rent" compared to the rest of the sector - why would anyone buy an Audi A4 otherwise? Ford are not so good at it. Certainly there was a desire to protect the Land Rover brand from customers drifting to Volvo. They also stunted Jaguar's growth in their ownership by keeping it too traditional and staid. Can you imagine how popular the X-Type would have been if there was an "R" version with the T5 Volvo engine (as they did with with the Focus RS). Another point to note is that when BMW sold the Rover Group and Ford acquired Land Rover, Ford insisted that Rover were contractually prohibited from selling any AWD/4WD cars. I doubt this would have saved Rover from their fate but a AWD 75 estate might have been a seller....

Originally Posted by JJJ

Even pulling off in Standard mode, the Haldex is enabled until 40km/h, before switching to (mostly) front wheel drive.

What I would have liked to see on the Volvo was at least an "offroad" button which ensured that it remains 4-wheel drive, regardless.

Depends on the Haldex version - "Instant Traction" models (MY2007-> and 3rd gen Haldex) retain AWD to around 15 mph *I think* and the 4th Gen Haldex models (MY 2009 ->) to a higher speed. I would expect the main reason it's not engaged for longer is friction and heating in the coupling due to rotational speed differences between the axles. Even on the very early Haldex AWD Volvo models in 2003, the time to engage rear drive is 1/7th of a wheel rotation.

Originally Posted by JJJ

Due to the above differences I am gathering information to see if I could go the same places the Freelander 2 has taken me. It will not be able to do so in standard form, but e.g. the excessive front overhang could be improved by a 20mm lift, or possibly modifying a used front bumper skin so the chin picks up.

I think there is no doubt that it will, the AWD system is essentially as capable, but as you have identified you just need to add the protection. The down side is there are far less off road accessories available.

You might find this interestiing, it's worth pointing out that the Volvo models featured are early ones - the first with Haldex. Another issue is that for the AWD system to work properly on Haldex equipped cars - the brakes MUST be in tip top condition as in the absence of limited slip/locking diffs, the system applies the brakes to individual spinning wheels to re-distribute the power. However only limited braking effort can be applied in this way and if the brakes are weak (especially rear brakes on cars with rusty discs etc.) then the whole system is compromised.

https://www.youtube.com/watch?v=tpp5tW71qYI

[JJJ]

Originally Posted by Tannaton

Another issue is that for the AWD system to work properly on Haldex equipped cars - the brakes MUST be in tip top condition as in the absence of limited slip/locking diffs, the system applies the brakes to individual spinning wheels to re-distribute the power. However only limited braking effort can be applied in this way and if the brakes are weak (especially rear brakes on cars with rusty discs etc.) then the whole system is compromised.

Thanks for your response. I found it useful. In support of that, the following:

We are now going slightly off-topic - towards Land Rover - but a while back a few local 4x4 forumites and myself went on a "softroader" outing to a track with hills, holes, rocks, cross-axles etc to compare the different softroader abilities: Tiguan, new XTrail, Duster, my 2007 i6, a 2012 SD4 and a 2012 Evoque.

As expected, the LRs cleaned up. However, what was very puzzling, was the Evoque being noticeably better than the two Freelanders. The TC kicked in almost immediately on cross-axles, the car maintaining momentum, where on the LR2s it "thought" a bit before regaining motion. Totally effortless.

My car was the worst, as it had Hankook road tyres on, where the other two vehicles had one profile larger AT tyres. The Evoque had particularly good grip with Cooper ZEON tyres on 19" rims.

So - apologies, this is a long story - the Evoque owner queried this with Land Rover SA, with video clips that was shot of the various vehicles' performance - see post #193 here: https://www.4x4community.co.za/forum...r-II-vs-Terios.

Land Rover then invited the two of us to an exclusive - free - day at their LR Offroad Experience facility, with a lecture on the principles and two instructors taking us through the obstacle course, where we pretty much saw the same behaviour, but still without a convincing explanation why this was so.

I subsequently called a dealer technical department and was told they have different SW. Yes/no/maybe??? Anyway, at the track they also threw in a Discovery Sport for our use to see how that compares. We could take turns driving it over the same obstacles. Based on that experience, I don't want one, hence this research into an XC60. XC40 initially, but I gave up, as they are too new and expensive, and locally Volvos have terrible resale value.

Then, the SD4 guy came with googled information that the Evoque's braking system is an uprated version - better brake boost - of the Freelander. He also stated that from his car, when the brakes are warm, the TC is more responsive. At the time, I had Ferodo Premium brake pads fitted and I know from experience they were too hard for the car - they had to be deglazed frequently. If a set of front brake pads on a 1.9ton car lasts just under 100000km, you must know something is amiss.

So all this confirms your statement above, and something I find logical. How come you know all this stuff?

Originally Posted by Tannaton

...but as you have identified you just need to add the protection. The down side is there are far less off road accessories available.

This is not a problem. I design and make my own.

[Tannaton]

Originally Posted by JJJ

Then, the SD4 guy came with googled information that the Evoque's braking system is an uprated version - better brake boost - of the Freelander. He also stated that from his car, when the brakes are warm, the TC is more responsive. At the time, I had Ferodo Premium brake pads fitted and I know from experience they were too hard for the car - they had to be deglazed frequently. If a set of front brake pads on a 1.9ton car lasts just under 100000km, you must know something is amiss.

So all this confirms your statement above, and something I find logical.

Here we go on another one....

And the reason why the Evoque did better (even with road tyres) is that it has a electronic parking brake (EPB), the LR2 does not.

Why?

On vehicles that have electronic parking brake, there must be a mechanism of bring the car to a halt from speed if the mechanical side of the service brake system fails. Hence if you have a car with an electronic parking brake, and you press the button over around 5mph, you will find the vehicle slams the brake on all four wheels and feathers the deceleration using the ABS system. Don't try it if anyone is behind you....

To enable the above, the electronically commanded application of brake ("brake boost" as you referred to it) needs to be much stronger, so the systems are upgraded, and this improves also the effectiveness of the traction control/AWD system when it needs to apply the brakes to balance power across an axle.

This may not be the same across all manufacturers but I'm sure it's relevant to Ford/Volvo/LR/Jag etc. Another point is that the above feature does not utilise the parking brake system, it's all done though the hydraulics. The same system is also used on those cars to facilitate "auto hold" - i.e. you wont roll back on a hill when setting off.

So - if you have an old XC90/XC70 that's known to frequently cross-axle - overhaul your brakes with quality parts...

FYI I love Cooper tyres - have them on my XC90 and Ford Ranger. Good value, perform well, road and off road variants.

EDIT: The XC60 has a EPB...