SLIP TEST - Volvo XC70 - V70 XC AWD vs Audi A6 C5 Allroad - @4x4.tests.on.rollers

Volvo XC70 2.4T AT AWD (2001)
vs
Audi A6 Allroad 2.7T MT Quattro (2003)

#duszaniespokojna #volvoxc70 #audiallroad

[john]

The thing about the Torsen center differential is that it generates a locking torque proportional to the drive torque only within the locking range of the differential. As the locking range for the Torsen Type A center differential on this allroad is from 77/23-23/77 (approx. 3.5:1 torque bias ratio on both axles as this is a symmetrical center diff), we should already know that the Torsen will not get the car off the rollers (with either front or rear wheels on rollers) by itself as at least 23% of the drive force must be supported by the axle with the lower coefficient of friction. We also know that the coefficient of friction on the rollers is essentially zero as no drive torque can be supported. Additional deceleration will need to be applied by the EDL control in the form of brake application until the force applied equals the amount the gearbox output torque exceeds the locking range of the differential (since the entire usable drive force needs to be supported by only one axle). So in this case, 23% of the drive torque would have to be wasted to lock up the differential and 77% would be available for forward propulsion. Additionally, the literature from Audi states that the Torsen diff will not transfer drive torque to the tractive axle in the event that the opposite axle is raised off the ground or on a surface with near 0 friction coefficient. The purpose of the Torsen differential is to reduce the frequency of required EDL activation in normal driving on slick surfaces, not to deal with the worst case scenario depicted in this video. With that said, all of the above is not a criticism of the Audi Quattro system as I know that the system works well in the real world. My only reason for mentioning the facts stated above is to remind people that no road going vehicle without diff locks will make it off 3 rollers without intervention from EDL (or whatever the respective manufacturer refers to EDL as). So before anyone comments that the Quattro system is crap, we should remember that the mechanical parts of road going AWD systems for the most part are not capable of coping with the worst case scenario (the 3 wheel slip test) without electronic intervention. Consequently, it is really the programming of the traction control system that determines how a vehicle will cope in the 3 wheel test. And also remember that a manufacturer should not program their ESC to simply perform well in the 3 wheel test as they must take into account allowable slip values. Programming the system to be too aggressive could also cause tire scrub, increased tire and brake wear, as well increased brake temperature, and drivetrain windup in extreme circumstances. Lastly, as ESC is relatively new and both of these vehicles are older, we should not expect them to perform as well as newer vehicles since programming of ESC was not as sophisticated when these vehicles were manufactured.

[emils]

I have a xc70. Its a absolutly beast in off road

[ВетальНекрутенко]

These are some of the most informative videos on the AWD system. Thank you! I would also like to see Scoda Octavia Scout (2004-2012), I know that there are not so many of them)
Your videos help me make the right choice!

[saiiiiiii]

Had an XC90 a few years ago. Was a blast to drive in snow👍

[bobmusick]

Having owned an allroad and seeing what Quattro used to be it makes me so sad that they nerfed the system. This video pretty much sums up my driving experience with it. When not flummoxed it was great but even a little slippage and you’re done (sans having good tires in certain situations). I adored everything about it but if I were to get another I would definitely love to retrofit some older locking diff system to it cause how can you tout having “legendary awd” when this clearly shows otherwise.

[IacopoRusconi]

Volvo XC70 the best Off road wagon ever!

[feralbii]

Volvo en vehículos el mejor del mundo, saludos y bendiciones desde Guatemala

[DIY-Mark-]

I regret selling my 01 V70-CC that car is king. But I do believe the Audi AWD is more advanced over Volvo. I now own XC60 T6 and V60-CC

[stevehoulihan]

And I thought Audi's quattro was the king! I've got an XC70 like this and I'm dying to try it out in snow. I really hope my Haldex works!

[Alejandro-svyl]

I only comment to support your video, your videos are very good and useful

[warphonesS]

I love my Xc70 seeing this makes me wanna somehow weld the rear diff.

[seventhson]

Great job Dusza! Would be interesting if you could reach some old 405, Escort, Audi 80 or other car from the 90s and compare it with something newer.

[LawatheMEid]

Any tests for volvo xc70 last model 2016?
Thanks.

[GERntleMAN]

Never had problems getting through deep snow, driving on changing surfaces with ice and snow or having control over the car with quattro. Problems only arise, where you need to be really slow and have the most unfortunate conditions possible.

[thecarsectionthecarsection]

No awd systems are great, so if you live where it snow have a shovel and if you off road have some rope.

[nitinbhugun]

Hi, can you do the 2006 2007 xc70? They have an better generation haldex. Thank you

[JoRMasteri]

Older V70 XC has diff lock in rear axle.

[whitefreeman]

well now we know.. neither of them are actually awd or 4x4.. thank you for your time invested in making this informative video

[vitaliimarushchak]

Mam auto skoda octavia 2 scout. Mieszkam w Krakowie.Duszniespokojna.

[hotstucominthru]

Have xc90 and xc70. I cant go back to anything else. Thats it. Im spoiled for life.