Why why why oh why has nobody grasped the point that a Yeti 4x4 is not a god damm 4x4. OK... there is a badge at the back of the car that says its a 4x4 and a stupid gearknob plasticky thing that also sugests its a 4x4.......but its not. Its the same for the Golf 4x4. version....its not permenant. The Golf and Yeti are not 4x4's Fact, end of. Enough with this 4x4 business....its giving my arse a headache.

What is your definition of a 4x4 if its not a vehicle where all 4 wheels are powered?

What is your definition of a 4x4 if its not a vehicle where all 4 wheels are powered?

99.999999999999999999 % of the time only the front wheels are driving the car. (Ok 5 % to the back wheels). I can tell that just by looking at the condition of my two back wheels which have not hardly used any tread in two years.

Edited 29 July, 201312 yr by MCAMRA

99.999999999999999999 % of the time only the front wheels are driving the car. (Ok 5 % to the back wheels). I can tell that just by looking at the condition of my two back wheels which have not hardly used any tread in two years.

That's not answering the question, I know how Haldex works.

Because too much power through the front wheels leads to torque steer.

 

Torque steer is not because of being FWD, but because of uneven torque distribution to the front wheels.  I had a light and relatively powerful FWD car that had been properly engineered with equal-length half-shafts and there was no hint of torque steer.

 

Back to the original argument around the NEED for 4WD - well there's lots of stuff you don't NEED on a car - power, gadgets, power assistance yada yada but we choose to have them for comfort, convenience, safety, aesthetics or whatever floats our individual boats and meets our personal budgets.

 

I went for 4WD because I hang around equestrian pursuits and have got at least one 2WD car stuck in a muddy field.  I may also want to pull a horse trailer one day, and 4WD will give a traction advantage on grass etc.  On so-called 'summer tyres' (come on guys, they are not "summer" tyres, they are just not winter-optimised tyres) in last year's snow I easily made it home in conditions that were foxing many cars around me.

 

Besides, I'm not sure that this assertion that the Haldex IV-equipped Yeti is only 2WD until slip happens is true.  Haldex IV is proactive and can apply rear-ward torque before slip happens.  Plus I am pretty sure that the Haldex chimes in during normal driving too, for example when pulling away.  I also read somewhere that a small level of torque is fed to the rear all the time, but I can't find anything to back this up.

Edited 29 July, 201312 yr by weasley

Hmmm...  probably true on cars 10 or 20 years old but on a modern variable, electronically controlled 4x4 system, like the Yeti's, you will be hard pushed to EVER tell which wheels are driven.  So the above statement does not hold true.  What is typical "extreme" RWD behaviour?  Oversteer.  I dare you to get a 4x4 Yeti to oversteer and act like a RWD car!  You won't ever be able to.  

The key in the above statement was predictability. I don't think that inability to tell which wheels the torque is sent to at each particular instant always adds to safety. Besides, I was able to get my Yeti to oversteer and it was not very difficult to do: ESP doesn't kick in until the steering wheel is turned at a particular angle. So I think the experts are still right

Besides, I'm not sure that this assertion that the Haldex IV-equipped Yeti is only 2WD until slip happens is true.  Haldex IV is proactive and can apply rear-ward torque before slip happens.  Plus I am pretty sure that the Haldex chimes in during normal driving too, for example when pulling away.  I also read somewhere that a small level of torque is fed to the rear all the time, but I can't find anything to back this up.

Yes this is true.I have never noticed the front wheels spinning on mine before the rears kicked in. The car just goes without any noise or fuss. Haldex 4 definately takes input from the throttle and will provide full power to all wheels if you put your foot down.

That's not answering the question, I know how Haldex works.

......a car that has 'permanent' 4 wheel drive is a true 4x4. Am I missing the point here ?

.....its not permenant. ..

I've had two Land Rover 110's.  Neither had either a '4x4' badge on the back.  I could decide when to put the drive through to the front wheels by using a manual gearlever.

 

My Yeti has a Haldex under the spare wheel.  The car's electronics decide when to make the drive available to the rear wheels. 

 

A lot of people would consider the LR a true 4x4, despite the front wheel drive being at the driver's choice.  A lot of people would consider the Yeti+Haldex a true 4x4, despite the rear wheel drive being optional at the electronic system's choice. 

 

Semantics. 

I've had two Land Rover 110's.  Neither had either a '4x4' badge on the back.  I could decide when to put the drive through to the front wheels by using a manual gearlever.

 

They were quite rare, the very early 110's that still had the 4x4 and 4x2 boxes from the series models.

Once the 90 was out all coil sprung Land Rovers were full time 4x4 with just the manual locking centre diff.

......a car that has 'permanent' 4 wheel drive is a true 4x4. Am I missing the point here ?

So any car that is not locked to a 50/50 power split is not a 4x4 in your book? Almost every single 4 wheel drive vehicle in production has the torque distribution dynamically controlled by a computer just like Haldex powered vehicles.

They were quite rare, the very early 110's that still had the 4x4 and 4x2 boxes from the series models.

Once the 90 was out all coil sprung Land Rovers were full time 4x4 with just the manual locking centre diff.

You must be one of the younger fellas, Boss.  Coil springs?!

So any car that is not locked to a 50/50 power split is not a 4x4 in your book? Almost every single 4 wheel drive vehicle in production has the torque distribution dynamically controlled by a computer just like Haldex powered vehicles.

Any vehicle that gives 'permenant' traction to all 4 wheels can only be described as a true 4x4. The Yeti (forget the 5 %) is not a 4x4. Of course there are exceptions (where you can manually engaged the 4x4 system) however, ....the Yeti (in my book) is not one....as the driver cant overule the computer. Its not permanant.

What's your cutoff o master of nomenclature? 10%? 20%? 49.9%? It is permanent 4 wheel drive as all 4 wheels are permanently driven, just not in a pointless, inefficient manner.

 

I guess my car doesn't have a throttle either, since the computer just takes the reading of its position and various other sensors and does what it deems appropriate. Just like the Haldex controller.

Taken from this topic

99.999999999999999999 % of the time only the front wheels are driving the car. (Ok 5 % to the back wheels). I can tell that just by looking at the condition of my two back wheels which have not hardly used any tread in two years.

Erm, I think you've surely then passed the point of having moved your front pair of tyres to the back to get even wear?!

What's your cutoff o master of nomenclature? 10%? 20%? 49.9%? It is permanent 4 wheel drive as all 4 wheels are permanently driven, just not in a pointless, inefficient manner.

 

I guess my car doesn't have a throttle either, since the computer just takes the reading of its position and various other sensors and does what it deems appropriate. Just like the Haldex controller.

I have no idea. In order to install the system onto any given car I should imagine you would probably need to apply 'x' amount of permanent traction to the rear wheels just to get the system to collectively work.

5% of permanent traction on the rear wheels on a day to day basis means diddly squat.....and therefore refer you back to my earlier comments.

Erm, I think you've surely then passed the point of having moved your front pair of tyres to the back to get even wear?!

Its pick on me day. No, the fronts need changing soon and I want to change all four to the same marque....and keep a back tyre as spare on a steel rim.

All these threads on 2WD/4WD/winter tyres together must be providing nearly as many posts as MarieK's thread on waiting for/picking up/driving home Snowy -  did we know if she is happy with her new car? I may have missed it.

 

I'm grateful to forum members for bringing to my attention winter tyres, something that in nearly forty years of driving I've never even considered (and in fairness I live on the South Coast and we don't get a lot of extreme weather but I hadn't appreciated the effect on performance at lower temperatures).

 

What I'm getting from these threads is that it is pretty much unanimous that fitting winter tyres on the 2WD will help with both traction and safety through the winter months and between that and helping save the alloys from road salt the cost of a set of steel wheels seems to be a good investment.

 

The non-2WD camp seems to be split into two factions. There are those who need drive to all wheels because of a need/wish to go off-road beyond the reasonable capabilities of 2WD. I can understand this and assume under these conditions traction and predictability are going to be far more important than speed. The other group appear to justify the four wheel drive capability for road use on claims for better road holding, accelerations, steering etc. particularly in very poor weather conditions and arguing this as a safety benefit.

 

I think the safety argument may be overstated because of risk compensation. Various studies over the years have shown that as vehicles have become safer drivers have modified their behaviour to reflect those improvements - better brakes make it quicker to stop, reducing risk, drivers leave braking latter bringing the risk substantially back to where it was. There was a recent study that demonstrated that cars pass closer to cyclists wearing helmets than those without - the theory is that subconsciously drivers feel that where a cyclist is wearing a helmet the outcome of an accident is likely to be less severe i.e. there is reduced risk so they can drive closer.

 

If a driver in a "4x4" has more confidence in the capabilities of that vehicle than he/she might if driving the 2WD version of the same car and drives accordingly - faster, braking later, changing lanes more frequently etc. he/she potentially will take greater risks for the prevailing conditions, relying on the "better" technology. The down side of course is when something does go wrong the faster you go the more energy you are carrying - double the speed quadruples the energy - so in the event of an accident the damage to car and occupants (and whatever you hit) will be correspondingly greater. There is also the problem of reaction time and the physics of braking - you have a lot more time to react to an incident at 20 mph than at 50 mph (I use these figures simply because on another thread someone mentioned driving at 50mph in snow past other traffic crawling at 20mph as a benefit of having a 4x4).

 

So on the road in the real world, potentially the 4x4 driver will be safer than the 2WD driver, all other things being equally, provided he/she in the same manner as when driving a 2WD. If the advantages of four wheel drive are exploited to go faster etc. then it is likely that any safety benefits are illusory - until you hit something when the laws of conservation of energy come into effect to increase repair bills.

 

But at the end of the day, it will all comes down to personal choice and finance.

 

Just as an aside, I wonder what proportion of 4x4's have been sold with heated windscreens, which I would have thought a key safety feature where the decision to buy a 4x4 is safety-led. (From the options poll on another thread it seems that about 10% of Yetis are sold with the heated front screen - thanks for that 900000).

Just as an aside, I wonder what proportion of 4x4's have been sold with heated windscreens, which I would have thought a key safety feature where the decision to buy a 4x4 is safety-led.

Lots of good points in the above, but the final line is something I find interesting. I always wonder why people don't pick all the extra safety options cars come with, like curtain airbags etc. Surely your safety is worth the £200 or whatever up front?

 

But at the end of the day, it will all comes down to personal choice and finance.

 

Just as an aside, I wonder what proportion of 4x4's have been sold with heated windscreens, which I would have thought a key safety feature where the decision to buy a 4x4 is safety-led.

 

Good points and as you say - comes down to finance. Or wanting the 140 diesel with a DSG that ONLY comes as a 4x4...

 

As to the windscreen:  this might help.

Paul52

I very much enjoyed reading your post and totally agree with everything you have said.

I feel though you have missed one vital piece to the jigsaw and that is the psychology and competence of other drivers around you. Not discounting of course that any piece of safety technology an individual chooses to install on their car is limited only to the fashion that those individuals choose to drive their car, but just as importantly you can never really adequately adjust your own driving style to compensate for those on the road who have no due regard or respect for you or their own safety ! I myself will try an install my car with as much 'safety' technology that (as you and the above posters have pointed out) I can afford to protect myself from the supidity, recklessness and selfishness of other drivers....and not forgetting the ever changing weather !

My dad was a 'traffic policeman' in the 1960/70's and taught me one valuable lesson. 'Never be the meat in the sandwich'. Whether that is another car, tree or something else as equally less forgiving.

99.999999999999999999 % of the time only the front wheels are driving the car. (Ok 5 % to the back wheels). I can tell that just by looking at the condition of my two back wheels which have not hardly used any tread in two years.

Could you be a bit more precise please?

Could you be a bit more precise please?

recurring !

My dad was a 'traffic policeman' in the 1960/70's and taught me one valuable lesson. 'Never be the meat in the sandwich'. Whether that is another car, tree or something else as equally less forgiving.

 

Presumably he also told you that the most dangerous part of a car is the loose nut behind the steering wheel!  We can only do what we can - drive defensively and keep fingers crossed, although probably not whilst driving.

recurring !

And that too!