Forget 4x4s in this weather

[Supertramp]

A bit of an aside, but on the basis that this thread is likely to attract interested people who will have read up on the subject and/or have specific experience, here goes:

 

Some 4x4s have hill descent features, ie to crawl down muddy slopes. I presume these will work in a similar way when descending a steep icy/slushy/snowy hill. Is that correct? Does anyone know if different companies have been tested against each other to determine which, if any, have the best hill descent system?

 

---------- Post added 24-03-2013 at 16:32 ----------

 

 

I've wondered whether the recent move towards "eco" tyres, as manufacturers (both car and tyre) chase better fuel consumption and lower CO2 figures, has resulted in tyres with reduced lateral grooves and harder compounds, even less suitable for winter use.

 

Proper 4x4 have hill descent systems like a Hilux or a Defender, but 'soft' ones like my sistersl's HRV doesn't so even if you crawl down the hill in first if you touch the brakes you lock up on ice and 4x4 won't help you then. Not sure if the hill descent feature would help you here?

[geared]

Does anyone know if different companies have been tested against each other to determine which, if any, have the best hill descent system?

 

Could probably find a car magazine thats done it.

 

Thing is tho people don't stop to think when driving around in the 'range'.

They certainly don't stop to engage hill descent mode.

I think most don't even think to engage 4WD mode, they just expect the vehicle to do everything automatically and to make them a driving god.

[vinyl]

Why buy a 4x4 and pay the extra fuel and tax not to mention the other running costs, the way forward is winter tyres, i've not been stuck once and they practically turn your car into a 4x4 anyway.

 

The amount of astonished faces that has seen me drive up steep snowy hills was great to see.

 

It's more a case of ground clearance. It's no use sticking winter tyres on a car with a front spoiler 4 inches above the ground and expecting it to get through 8 inches of snow.

 

4*4s don't need to be any bigger than 2 wheel drives. I've had Audi A4 Quattros and they do Fiat 4*4s with engines as small as you like.

 

Try stopping at the traffic lights half way up Meadowhead when its icy and then setting off again with FWD.

 

The winter this year has hardly seen proper snow. Its OK driving around town but try crossing the Yorkshire Wolds when there's a sudden blizzard.

 

---------- Post added 24-03-2013 at 17:48 ----------

 

Proper 4x4 have hill descent systems like a Hilux or a Defender, but 'soft' ones like my sistersl's HRV doesn't so even if you crawl down the hill in first if you touch the brakes you lock up on ice and 4x4 won't help you then. Not sure if the hill descent feature would help you here?

 

Your antilock brakes and 4 wheel drive won't allow individual wheels to lock.

[biotechpete]

 

I've wondered whether the recent move towards "eco" tyres, as manufacturers (both car and tyre) chase better fuel consumption and lower CO2 figures, has resulted in tyres with reduced lateral grooves and harder compounds, even less suitable for winter use.

 

When you look at the road tests for the michelin summer energy saver, it performs pretty well in the wet, though I think not well in snow, so I guess it's more of a compound issue than anything else.

 

 

 

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[Cyclone]

Is it safe to ride a horse when its icy?

 

Probably not, but I expect that they still need to eat.

 

---------- Post added 24-03-2013 at 18:04 ----------

 

I've pulled Landrovers on summer rubber up hills before now, using a BMW with winters fitted. If I had the choice I'd pick 2WD winters over a regular 4WD on summer tyres every time.

 

But 4WD on winter tyres would be the best option.

 

---------- Post added 24-03-2013 at 18:08 ----------

 

But how many 2 wheel drive vehicles have succumbed to the recent weather?

Yesterday I was out and about in my Landrover. I went down Gleadless rd, Roebuck rd up Chesterfield road and past buses, cars and HGV stuck in the snow.

Driving was a piece of cake. It was just a matter of selecting low ratio and letting the engine control the speed of the vehicle when going down hill.

The problem with modern 4 wheel drive vehicles is that they do not have high and low ratio.

My wife has a CRV and it is a very good vehicle in adverse weather but for yesterday's scenario we used my vehicle to get her to work as I would not have risked it down Gleadless rd.

 

I wouldn't think that 4WD makes a huge difference on a descent. You can do the same thing with a FWD car (ie in 1st gear, downhill at tickover speed), it's controlling the speed using 2 wheels instead of 4 of course, but I wonder if you can't achieve 4 wheel retardation by pulling the handbrake on 1 or 2 clicks, not enough to lock the back wheels of course, just enough so that they are taking some of the load as well.

[Eater Sundae]

When you look at the road tests for the michelin summer energy saver, it performs pretty well in the wet, though I think not well in snow, so I guess it's more of a compound issue than anything else.

 

 

 

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When I was researching tyres (before buying my 4 season ones), I tried to find out about compounds. Winter tyres are advertised as best below 7 deg (and presumaly summer are above 7), but I couldn't find if 4 season tyres used a summer compound with a winter tread or winter compound in a less wintery tread, or some other combination of compound and tread. Certainly the information said that 4 season tyres are very close to winter tyres.

 

---------- Post added 24-03-2013 at 19:05 ----------

 

When you look at the road tests for the michelin summer energy saver, it performs pretty well in the wet, though I think not well in snow, so I guess it's more of a compound issue than anything else.

 

 

 

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I think the braking performance in the wet (in summer conditions) is mainly dependant on the ability of the tyre to push water to the side to allow the rubber to contact the road. In the case of snow, the proper winter tyre relies on the fine lateral grooves (called sipes, IIRC?) to trap snow which itself grips the snow on the road. The flexibility of the winter compound also allows the tyre to still flex at the low temperature. However in dry conditions it is probably more down to the compound.

[HappyCampers]

I wouldn't think that 4WD makes a huge difference on a descent. You can do the same thing with a FWD car (ie in 1st gear, downhill at tickover speed), it's controlling the speed using 2 wheels instead of 4 of course, but I wonder if you can't achieve 4 wheel retardation by pulling the handbrake on 1 or 2 clicks, not enough to lock the back wheels of course, just enough so that they are taking some of the load as well.

 

Not sure you want to 'click' the handbrake, if you are going to do this hold the handbrake button in so you can release immediately if you need to - usually 1 wheel locks well before the other. 4WD descending is better (usually) in that it feels much more in control/balanced

 

My old Nissan 4x4 had diff locks too which really are awesome. Alas, the thing had rubbish Wanli tyres when we got it - you could engage full 4WD and diff locks and still go no where as it span all 4 wheels - funny though. Decent all season tyres made a world of difference

[AF Removals]

Because no car with winter tyres looks as sik as my disco 3 on 22s

[Eater Sundae]

Do you have just the tyres or do you also have a spare set of rims?

 

I keep meaning to put some winter boots on the car but would probably get a spare set of rims too so I could swap over myself. We're getting a new car next year so will probably just manage next winter as we do now (not use the car in snow) - however, for my next car I will definitely get a set of winter tyres too.

 

If you've got the space to store them, and you are keeping the car long enough to justify the up front cost of two sets of tyres, and provided you are prepared to set aside an hour or so twice a year to swap them, then I think it's better to get a set of winters on a set of steel rims. You will save the cost of having a tyre fitter swapping them over (which will take longer than you changing the wheels at home), you will protect your expensive alloys (if you have them) from salt on the roads, and you have a ready made opportunity to check over your tyres (while they are off the car) for cuts, nails etc before they have the chance to work their way through the tyre.

 

Complete wheels are available from on line sellers such as My Tyres. The rims are about £30 to £50, IIRC, depending on the size of the wheel.

[monkey104]

Probably not, but I expect that they still need to eat.

 

---------- Post added 24-03-2013 at 18:04 ----------

 

 

But 4WD on winter tyres would be the best option.

 

---------- Post added 24-03-2013 at 18:08 ----------

 

 

I wouldn't think that 4WD makes a huge difference on a descent. You can do the same thing with a FWD car (ie in 1st gear, downhill at tickover speed), it's controlling the speed using 2 wheels instead of 4 of course,

 

On ice just slightly applying the brakes will lock the wheels up.

On low range all four wheels are been driven by the engine. When going downhill you take your feet off the brakes and let the engine predict the speed.

Anyone who has ever driven a vehicle in low range will know this.