So what's the easiest way to cope with icy and snowy roads?

[Dave Newell]

With the current road conditions around here in the Midlands i thought it an opportune moment to remind people how to keep moving while all around you people are struggling for grip.

 

It's quite simple really, let your drive wheel tyres down to around 5psi! The tyres will then flatten out and can mould themselves around the ground and snow/ice. I guaranteee you will be amazed howw much grip there actually is.

 

Once you've let your tyres down proceed slowly and carefully using mnimium engine revs and make all adjustments smoothly, throttle, brakes and steering wise. If you find yourself in start stop traffic then wait till you have a couple of car lengths clear between the car in front and yourself before you move up, this will reduce the wear on your clutch. When stationary select neutral and apply the handbrake, don't sit there in gear riding the clutch, you're only wearing it out faster.

 

D.

[Guest starspirit]

Agreed Dave, but do please make sure you have a 12v inflator and/or footpump with you and don't give the drivetrain any stick or you might just pull the tyres away from the rims which would be sort of inconvenient.

[colin]

I had a good trip into work yesterday, hardly any cars on road as schools where shut, mainly vans, most driven at sensible speeds with good spacing, the worst diving I saw was a tranny appearing out of the gloom with no lights a windscreen with small cleared area and a woman driver on her mobile, I wonder what her crash rate is like?

[Dave Newell]

It was quite amusing to see how many 4X4 drivers thought they were immune to traction problems only to find themselves at the controls (or not) of a 2 Tonne sledge!!

 

D.

[twooks]

Dave, presume that's 5psi in a car, with more in the van??? cos it seems awfully low for my van?

Use to borrow a car with winter tyres about 100 years ago when I lived where it snowed, made a tremendous difference. We should be prepared to do that more often here - problem is - where would you store them during our glorious sunny summer weather :->

 

 

B-)

[Dave Newell]

No Twooks, 5 psi in anything. for a short distance (even up to a couple of miles) at low speed (less than 20MPH) it will not hurt the tyres but as soon as you get on to good roads you should pull over and re-inflate to the correct pressures with your 12 Volt compressor, you d ocarry one don't you?

 

D.

[twooks]

of course *-) has it's own little niche in the van - good for the bike tyres in the van and m-in-laws wheelchair tyres when in the car. The trick is remembering to transfer it between 2 vehicles so that's in the right place at the right time *-) :-(

 

B-)

 

we did have 2 - but b-in-law 'borrowed' it a while ago!!

[Derek Uzzell]

If you lower the pressure in a motorhome tyre to near-zero, when you come to reinflate the tyre to its normal pressure, you better have a) plenty of time on your hands and b) a damn good 12V pump that will tolerate extended-duration operation.

[Dave Newell]

True Derek but if you can get them up to 25-30 psi you could then drive slowly and safely to a petrol station to re-inflate them fully (assuming the forecourt pump can handle the required pressures).

 

D.

[David Dwight]

Hi Dave,

 

I have yet to find a forecourt tyre pressure machine that will inflate to the correct pressure. I usualy go to my local tyre depot.

 

David

[Guest JudgeMental]

David Dwight - 2007-02-10 9:50 AM

Hi Dave,

I have yet to find a forecourt tyre pressure machine that will inflate to the correct pressure. I usualy go to my local tyre depot.

David

 

Likewise, I bought a "Mitchlin" brand pump from Halfords 2 years ago for £25. It worked well with my 4X4 demountable camper.

[Bill]

Many years ago in South Africa we used to let our beach buggy tyres down in the same way, to handle beach sand. We found 8 psi low enough even for a very light vehicle like a buggy.

 

Another useful trick, which I have not seen anywhere else, is "twin handbrakes". Your normal handbrake cable has a splitter somewhere along its length, with one side going to the left wheel and one to the right. Connect each of these cables to a separate lever.

 

If you get stuck with one wheel spinning, simply pull on the handbrake on that side. Almost as effective as limited-slip diffs, 4wd etc, and a helluva lot cheaper!

 

[chas]

I would imagine driving several miles,even slowly on 5psi would knacker the walls of the tyres, far better to fit some studded snow tyres on the drive wheels, particulary if this type of weather may be more frequent due to all this globel warming forcasts. They are also a legal requirment in many european countrys. Snow chains could also be a cheaper option. chas

[twooks]

If I thought that I would have to drive in these conditions a lot then I would splash out on winter tyres, and come to some kind of storage arrangements. It is not yet that likely, and - to be honest - my main worry is the rest of the road users - as quoted in Dave's other post on this topic. If it was just up to me then I would hibernate until Spring. :->

 

B-)

[Brian Kirby]

Dave Newell - 2007-02-09 10:12 PM No Twooks, 5 psi in anything. for a short distance (even up to a couple of miles) at low speed (less than 20MPH) it will not hurt the tyres but as soon as you get on to good roads you should pull over and re-inflate to the correct pressures with your 12 Volt compressor, you d ocarry one don't you? D.

Well, its probably nearly all gone by now, so a bit late, but I would just add that this should not be done unless the normally inflated tyres really can't get any grip.  It is true the contact area increases with reduced pressures, but the pressure over that increased area in unit/area terms is reduced. 

It can work on snow, it is (in my opinion) of marginal benefit on ice.  One disadvantage is that once the snow lays in sufficient depth to obliterate all those little irregularities on the road, like low kerbs and the edges of traffic islands etc, that invariably get buried under the "splash" from the main carriageway, they are all too easy to drive over.  If you catch one of them with 5psi up, you'll probably do in a rim as well as a tyre, even at 20 mph.

As an inhabitant of the snowy wastes of the South East, I recommend:

a) Absolute minimal throttle and highest feasible gear,

b) Keep engine speed just above, but as close as possible to, stalling. 

c) Stay well up the camber. 

d) Brake a little possible, using the engine brake until the last few yards. 

e) Don't stop on hills, stop at the bottom, wait for traffic to clear and then drive gently (in the highest possible gear) up without further gear changing. 

f) Use powder snow wherever possible to aid traction. 

g) Assess any hill very carafully before tackling it, either up or down - downhill on ice, when tyre grip is lower than gravitational attraction, is quite exciting! 

h) Avoid at all costs 4x4 s.  Most of their drivers seem to forget we've all only got 4 wheel brakes!

[Dave Newell]

Actually Brian it works very well on ice, I first saw it on a programme by Jezza Clarkson in Iceland where he went on a glacier expedition. They take you in 4X4s with big balloon tyres up to the glacier then let the tyres down to 1/2 PSI (yes that's a half pound per square inch) they then drive up the slopes of the glacier. Every now and then a tyre will fall off its rim but they have an easy way of dealing with this. (now I don't recomend anybody tries this) the passenger gets out while the driver carries on. Passenger sprays lighter fuel round the inside of the displaced tyre then ignites the fuel stream with a ciggy lighter. The rapid expansion of the air inside the tyre literally blows it back onto the rim.

 

I succesfully did about twenty hill starts on sheet ice yesterday afternoon but you are right, powder snow does give better grip. The hidden kerbs are a danger as you point out but the benefit is by going slowly you have much more control. All the other vehicles in the queue with us were getting major wheelspin, including all the 4X4s I saw and were slewing wildly from one side of the road to the other. We had no such problems, just raise engine revs to about 1100 and gently let in the clutch, minimum wheelspin (in fact wheel slip would be more accurate) occurred and we pulled away smoothly.

 

This method is ONLY for use in EXTREME conditions but to be honest just letting your tyres down to half their normal pressure will help.

 

D.

 

P.S. 4X4 drivers are very funny in the snow and ice when they think that all wheel drive gives them an advantage but there faces are a picture when they hit ice and find themselves at the controls(?) of a two Tonne sledge!

[Brian Kirby]

Dave Newell - 2007-02-10 6:16 PM Actually Brian it works very well on ice, I first saw it on a programme by Jezza Clarkson in Iceland where he went on a glacier expedition. They take you in 4X4s with big balloon tyres up to the glacier then let the tyres down to 1/2 PSI (yes that's a half pound per square inch) they then drive up the slopes of the glacier. Every now and then a tyre will fall off its rim but they have an easy way of dealing with this. (now I don't recomend anybody tries this) the passenger gets out while the driver carries on. Passenger sprays lighter fuel round the inside of the displaced tyre then ignites the fuel stream with a ciggy lighter. The rapid expansion of the air inside the tyre literally blows it back onto the rim. I succesfully did about twenty hill starts on sheet ice yesterday afternoon but you are right, powder snow does give better grip. The hidden kerbs are a danger as you point out but the benefit is by going slowly you have much more control. All the other vehicles in the queue with us were getting major wheelspin, including all the 4X4s I saw and were slewing wildly from one side of the road to the other. We had no such problems, just raise engine revs to about 1100 and gently let in the clutch, minimum wheelspin (in fact wheel slip would be more accurate) occurred and we pulled away smoothly. This method is ONLY for use in EXTREME conditions but to be honest just letting your tyres down to half their normal pressure will help. D. P.S. 4X4 drivers are very funny in the snow and ice when they think that all wheel drive gives them an advantage but there faces are a picture when they hit ice and find themselves at the controls(?) of a two Tonne sledge!

Hello Dave

Yes, I saw the programme as well.  However, the vehicles were on big baloon tyres, so lots more air inside to expand when heated. 

If 4x4s were spinning and sliding it was only because their drivers didn't know how to handle the conditions.  Low revs, highest possible gear!  If that doesn't work either get out and walk, or play with the tyre pressures.  Best fun is wet ice, which I guess is what you had.

Sometimes even the camber is enough to start the slide, and you just end up at the kerb!  Don't get out of the diver's door if this happens, that is unless you like the view from under your 'van.  :-)