VW Tiguan - Why Snow Chains on Front Wheels Only?

[segart]

Hi Guys,
The 'destructions' for my VW Tiguan 4Motion Escape 2009, say that I can put snow chains on the front wheels only. Anyone got any idea why, and what would hgappen if I put them on the rears? The reason I ask is that I have a set of chains which fit the wheels (235 55 17) but there is a disc guard very close to the tyre on the fronts, that makes the chains a really tight fit and I think they would actually grind against it. Any ideas?
Cheers
Rick

[SwissJonese]

Normally to fit chains you need a smaller wheel e.g. my C350 had 18inch alloys, but for Winters I had 17inch to allow clearance for snow chains and higher tyre tread. But it does sound odd to only install chains on the front. Maybe it is setup for the front wheeled version of Tiguan only, rather than the 4-motion?

[tigger1]

Don't know the answer - but logically, if you fit chains to the rear (only), how do you plan to steer the car? 4wd, so I guess the front wheels will slip a little when accelerating before power is sent to rear too, which could make handling even more interesting at the front.

Similarly, if you fit chains to the front, will there be any power to the rear wheels?

ETA: take the above with a massive pinch of salt, I'm probably talking rubbish.

[segart]

SwissJonese said:

Normally to fit chains you need a smaller wheel e.g. my C350 had 18inch alloys, but for Winters I had 17inch to allow clearance for snow chains and higher tyre tread. But it does sound odd to only install chains on the front. Maybe it is setup for the front wheeled version of Tiguan only, rather than the 4-motion?

That's a good point. The manual could be generic for all versions. I will take a closer look at it. Cheers rick

[catso]

Obviously chains would normally be fitted to the driven wheels on a 2 wheel drive vehicle as such a front wheel drive vehicle with chains would be better on snow due to having grip on the wheels that steer and drive rather than just the drive.

A 4 wheel drive vehicle would obviously work better with chains on all 4 wheels (as would a 2-wheel drive actually) but if you only have 2 chains then you should fit to the front so that you get the benefit of grip to the wheels that both steer and drive (also most of the braking), the rears will have to slip...

[mikecassie]

Isn't the Tiguan a 4wd only when the front wheels slip a little, like most VW's and Audi's? The Haldex diff usually slips and lets the rears just freewheel, once it senses slip at the front, the diff begins to transfer torque to the rear until it reaches it's max setting, 60/40, 50/50 or whatever the boffins think is best.
If that is the case, maybe that is why the Manual says that, it only needs chains on the front as they do the majority if not all the work, steering and traction. The rears having chains would not provide any benefit until the fronts slipped and then it could be too late?
I'm sure someone with more VW knowledge will provide better info soon.

[anonymous-user]

mikecassie said:

Isn't the Tiguan a 4wd only when the front wheels slip a little, like most VW's and Audi's? The Haldex diff usually slips and lets the rears just freewheel, once it senses slip at the front, the diff begins to transfer torque to the rear until it reaches it's max setting, 60/40, 50/50 or whatever the boffins think is best.
If that is the case, maybe that is why the Manual says that, it only needs chains on the front as they do the majority if not all the work, steering and traction. The rears having chains would not provide any benefit until the fronts slipped and then it could be too late?
I'm sure someone with more VW knowledge will provide better info soon.

I would go with this. Front wheels only on this type of 4WD works well - just watch the back end on turns and braking. Adding a set at the back will increase understeer when front loses traction which is a nasty combination on roads meaning you could veer into oncoming traffic. Easier to catch the back end than sail head first into lorry coming the other way. Or fit 4 for optimum traction and just take it easy around the bends

[thebraketester]

What mikecassie said. 4motion is haldex and is a non permenant 4wd system where the rear wheels are often not driven.

[segart]

mikecassie said:

Isn't the Tiguan a 4wd only when the front wheels slip a little, like most VW's and Audi's? The Haldex diff usually slips and lets the rears just freewheel, once it senses slip at the front, the diff begins to transfer torque to the rear until it reaches it's max setting, 60/40, 50/50 or whatever the boffins think is best.
If that is the case, maybe that is why the Manual says that, it only needs chains on the front as they do the majority if not all the work, steering and traction. The rears having chains would not provide any benefit until the fronts slipped and then it could be too late?
I'm sure someone with more VW knowledge will provide better info soon.

Thanks Mike that makes loads of sense.
Cheers
Rick

[Kawasicki]

Plenty of full time awd cars only need snowchains on the front axle, it is not unusual. I think the main reason is convenience.