Stuck in snow?

[slim_boy_fat]

I found a cheaper way, Just parked it up and used a bus pass till the snow had gone

Ideal if you have a) public transport, and b) such as there is will get you to your destination without having to hang about, waiting to catch onward services.

 

[normspanners]

the difference between 8 and 5 psi etc nice comparison

Deflating-Inflating
When driving a mountain truck in difficult conditions, the air-pressure in the tires can make a big difference for the Arctic Trucks. Drivers have to evaluate the surface and find the right pressure in the tires. Deflating the tires is essential when driving in snow and important to find the right pressure for conditions each time.

When the tires have been deflated the tires get a larger contact area with the surface, which gives more grip and flotation. Deflated tires also give a softer ride on rough roads. Unfortunetly deflated tires are more vulnareble to damage and will puncture easily. Therefore it is important to drive slowly, avoid sharp rocks, pot-holes and other things that might damage the tire.

After the driving conditions improve the tires should always be inflated as soon as possible.

from http://arctictrucks.com/Experiences/Icelandic-expedition/Blog.aspx

 

[slim_boy_fat]

For the snow

That's cheating......

 

[skotl]

Similar experience for me with the BMWs - had an automatic E39 540i and it once took me and two lovely carpet fitters (they were just passing by) two hours to get it out of a parking space that was on a mild incline.

Best ever car in the snow? A Mitsubishi 3000GT twin turbo bought for £6k in the 90s four wheel drive and four wheel steering, and the low nose acted as a snow plough!

 

[nickk]

I well remember Marina vans in the snow

I bet you do,that’s because BL build quality created gaps around the doors to allow snow thru.

 

[Migmac]

Well been VERY successful for me !! I always drop the pressures down and has got me out when stuck or in bad conditions. One time I was in a forrest and there was no way my tranny was coming back up the hill and all attempts failed but each was making the conditions worse so dropped the pressure to about 5 / 10psi and she came out without spinning a wheel had a slow drive about 8mls to a garage to reinflate but it was better than a 5ml walk in snow just to get out the forest
this shows it nicely

http://arctictrucks.com/Experiences/Icelandic-expedition/Blog.aspx


Also I think the icelandics would know they run at about 5 psi on snow !! when I was there in the perma snow I was amazed just how low they do go.

Yes large cable ties worked fine anything to alter the shape of the tyre.
I once went to andora skiing in an rover SD1 not known for their snow ability and it was a nightmare the kids nursery was at the mid station so you had to take/ carry your 2 yr old on a ski on ski off seat lift !!! did it the first day but never again I dropped the pressures and put chains on the rears and drove up the mountain access road to the nursery every day, some times through 10 ins of fresh snow, only day I couldnt was coz of an avalanche and even the machines could nt get up! so that was fair enough.

h

I’ll be like British rail then and blame the type of snow we had

 

[normspanners]

I’ll be like British rail then and blame the type of snow we had

???

 

[reb78]

Bear in mind that a lot of modern cars come from the factory and are continued to be fitted with run flats. I dont think deflating these will do much at all, in fact it might make them handle very badly given that you will be travelling on the discs that are the hard wall of the tyre. It may also damage the tyre shoulders irreparably....

 

[slim_boy_fat]

h

I’ll be like British rail then and blame the type of snow we had

You're thinking about leaves.....

 

[Migmac]

???

British rail blame leaves for stoping trains, I just put my twist on it by saying wrong type of snow instead of leaves for me not getting out of snow successfully with deflated tires

 

[GW8IZR]

At the end of the day you will sometimes get to a point where there just isn't sufficient friction to maintain traction whatever you try. Now a slightly different tread pattern or a slightly different weight distribution may work just that bit better and you will sail past another driver feeling smug - sometimes you will watch them go past and think doh!

Anyway airing down the tyres is of course effective and has been used for many years by people that have to drive in the snow and it works. I've done it loads of times and it will sometimes give just enough extra to get moving... and that is all it takes.

Then at some point you need to drive on a surface where the tyre could be damaged by the under inflation - so you have to act accordingly.

The Genie lift in my avatar was 'so stuck' it was needing a crane to get it out of a drift... I walked up to it and swung the boom over to the side transferring the weight and just drove it out to the road. Sometimes we get lucky......

 

[Sean]

Also I think the icelandics would know they run at about 5 psi on snow !! when I was there in the perma snow I was amazed just how low they do go.

Depends if you want to float over deep snow or cut through it to firmer surface below WRC cars use relatively

narrow tyres
https://www.walldevil.com/wallpapers/w10/subaru-rally-cars-snow.jpg

 

[bricol]

Rally tyres are a bit different though - lot softer, lot deeper tread, and way longer studs than you are normally allowed (infact I seem to recall we might not be allowed to use studded tyres on UK roads?).

Rally driving a bit different too - while you might see Granny opposite locking down to the Co-op, it's normally at 5mpg, all wheels locked up, screaming . . . rather than throttle to the floor aiming for the apex ;-)

 

[normspanners]

while you might see Granny opposite locking down to the Co-op, it's normally at 5mpg, all wheels locked up, screaming

HEHE try going to Scandinavian countries the taxi drivers are often grannies and they drive sideways most of the time, chatting away about the time of day whilst on snow covered roads. No screaming though well not from the driver unaccustomed passengers maybe .

 

[Turbo]

My dad heard a good one today at the petrol station. The attendant told him that he had driven home last night with the handbrake half on to help him grip in the snow!

 

[PhillipM]

Yep, helps in stuff like MX5's, etc, which have a torsen diff - they can only shuffle power as a multiple of what's at the other wheel, applying the handbrake lets them move more power over to the wheel with traction if one wheel is on very slippy snow/ice.

 

[normspanners]

Yep, helps in stuff like MX5's, etc, which have a torsen diff

Yes I agree Torsens only work when they work against something they are really only a 'road' diff if you lift a wheel cornering you lose lsd effect. unless you have a preloaded torsen

this explains it better
When attempting to turn with a torque sensitive differential, the outer wheel will rotate faster relative to the differential, and the inner wheel will rotate slower than the differential. Friction in the differential will oppose motion, and that will work to slow the faster side and speed up the slower/inner side. This leads to asymmetric torque distributions in drive wheels, matching the TBR. Cornering in this manner will reduce the torque applied to the outer tire, leading to possibly greater cornering power, unless the inner wheel is overpowered (which is easier to do than with an open differential). When the inner tire (which has less traction due to weight transfer from lateral acceleration) is overpowered, it angularly accelerates up to the outer wheel speed (small percent wheel spin) and the differential locks, and if the traction difference does not exceed the TBR, the outer wheel will then have a higher torque applied to it. If the traction difference exceeds the TBR, the outer tire gets the tractive torque of the inner wheel multiplied by the TBR, and the remaining applied torque to the differential contributes to wheel spin up.

When a Torsen differential is employed, the slower-moving wheel always receives more torque than the faster-moving wheel. The Torsen T-2R RaceMaster is the only Torsen to have a preload clutch. So, even if a wheel is airborne, torque is applied to the other side. If one wheel were raised in the air, the regular Torsen units would act like an open differential, and no torque would be transferred to the other wheel. This is where the parking brake "trick" can help out. If the parking brake is applied, assuming that the parking brake applies even resistance to each side, then the drag to the airborne side is "multiplied" through the differential, and TBR times the drag torque is applied to the other side. So, the ground side would see (TBR X drag torque) minus drag torque, and that may restore motion either forward or in reverse. In Hummer/HMMWV applications, there are both front and rear Torsen differentials, so the use of the main brakes will operate this "trick" on both axles simultaneously.

 

[Robotstar5]

My dad heard a good one today at the petrol station. The attendant told him that he had driven home last night with the handbrake half on to help him grip in the snow!

I watched someone in a front wheel drive using a similar technique to get up a snow covered hill, he kept dabbing the brakes to transfer the power from the spinning wheel to the other with more traction, that and a bit of winding the steering side to side got him up the hill

 

[normspanners]

I watched someone in a front wheel drive using a similar technique to get up a snow covered hill, he kept dabbing the brakes to transfer the power from the spinning wheel to the other with more traction, that and a bit of winding the steering side to side got him up the hill

I thought that was normal driving ?? on snow------ front or rear wheel drive that is what your left foot is for----- especially in autos. You mustnt have driven tractors in boggy fields,?? that is how you keep going ! as soon as you feel wheel slip you dab that brake and you literally lurch forward. sometimes more effective than diff lock because YOU create an active axle ! once stuck with diff lock you are STUCK.
But in rear wheel drive you hand brake is you friend keep dabbing it will help you control drive wheel spin.
Trials cars even have 'fiddle' brakes like a tractor for keeping motion as well as tight turning.

 

[Seadog]

But in rear wheel drive you hand brake is you friend keep dabbing it will help you control drive wheel spin.

Try doing that in a Merc, Norm