SOT: Which car to use in snow?

[Dave Plowman (News)]

And you get lots and lots of snow in parts of the UK.

[The Other Mike]

Because it snows a lot in Northern Italy

[The Other Mike]

Not even any drive, it's one wheel still, three wheels spin.

[The Other Mike]

Good luck trying to reverse up a hill in snow particularly with any bends.

The answer is to have very low zero steering input and let the engine management system idle control drag you up the hill at the edge of traction. Zero user accelerator input, just idle speed in 2nd gear. Of course that needs a warm engine that can maintain say 700 rpm or less with varying wheel loads. In hindsight trying not to be distracted by the 4x4's 911's Jags and Beemers in the hedges is the hardest part. Been there done that got the t-shirt

[The Other Mike]

But still as shit when a diff housing gets grounded, at that point it becomes a shed with one wheel static and three wheels spinning all the power down the khazi.

If you want proper ability in adverse conditions with lumps in the middle of the track then you need something with portal axles like a Unimog or Haflinger or Pinzgauer and multiple diff locks such that sticking one wheel in the air doesn't strand the entire vehicle.

A more modern showroom standard vehicle like a Discovery or Range Rover with traction control, indiividual wheel braking and diff locks (as long as it's not screwed by electricial problems) will outperform any standard Defender in adverse conditions.

[charles]

I had the nasty experience of trying to reverse a Range Rover downhill backwards on a snow/ice covered track because the vehicle I was following got stuck. Yes, at least one bend before I got to somewhere I could turn.

[Dave Plowman (News)]

Having rigid axles which can dig into the snow is not as good an idea as a decent independant suspension where the diffs are located higher.

[Dave Plowman (News)]

That can certainly help in less than ideal conditions like a wet road, but is useless on ice, etc.

[Dave Plowman (News)]

You can't reverse other than in a straight line?

Best not to venture out in snow, then.

[Michael Chare]

Trouble is they won't fit the next vehicle you buy!

[The Natural Philosopher]

Freelander 1 has no center diff - just a viscous couopling that locks up when it detects froint wheel spin. Not sure if it has brakes fdor traction control

[David]

I can't answer your specific question, but I do recommend a watch of the ex cellent test that AutoExpress did to evaluate the effect of winter tyres. They took a couple of Ford Kugas (one 2WD and one 4WD) up an indoor ski slo pe, with a variety of different tyres.

You may be surprised at the result.

David

[The Natural Philosopher]

well yes, it shows the Ford Kuga 4WD to be a heap of shit

Point taken about winter tyres BUT my freelander does better than that on summer tyres, in snow

[Dave Plowman (News)]

A Range Rover being a 4X4 isn't going to make much difference traction wise going up a hill forwards or backwards. But with FWD only, it can make a very big difference.

[Andrew]

I had one. 1st gear would pull it up a 45 degree incline, but sadly they were made of baking foil so suffered badly from rust.

Nice comfy seats too.

[Andrew]

But rarely south of Manchester, apart from Brecon and Dartmoor.

[charles]

when some of the track was covered in ice, backwards became interesting, especially as the view for reversing in a RR isn't that great.

[Dave Plowman (News)]

And wasn't launched until a year after the FWD Panda, which was designed as a city car. Like pretty well all small cars at that time.

[Dave Liquorice]

would

Diffs are funny things, multiple diffs are just plain weird.

In the below:

"traction" - Wheel is not slipping/spinning. "drive" - Abilty to move.

I'm about 85% certain this is what happens with various drive and diff lock arrangements:

2WD un locked diff, one wheel loses traction, the other stays still, no drive.

2WD locked diff, both wheels are locked together and rotate at the same speed. If one loses traction, hopefully the other will still have traction and you'll have drive.

4WD un locked diffs. One wheel loses traction, you lose traction for that axle. The other axle still has drive.

4WD locked center diff. Both axles are locked and rotate at the same speed, note axle not wheel. A single wheel can lose traction and the other three wheels retain drive. Both wheels on the same axle can lose traction the other axle retains drive. If diagonal wheels loose traction, you loose drive at the other two wheels.

4WD center and axle diffs locked. Everything (axles and wheels) goes round at the same speed, wether any given wheel has traction or not. This can give you one wheel drive...

With a diff locked there is a risk of "transmission wind up" that can lead to broken half shafts or stripped diff gears. You should not lock diffs unless the surface is slippy enough to allow the wheels to rotate at different speeds, as they must do, as you go around corners.

[Dave Liquorice]

I found that the front valance got in the way before the diffs on a DII: