Diesels tend to be a little better in the snow than petrols just due to the weight over the front wheels and being a bit easier to drive at very low revs.

Best car I ever had in the snow was my first car. A crappy Astra Mk2 on cheap 155 tyres. Awful in anything else but the narrow hard rubber used to dig in and grip the snow. Ugly old bugger never ever got stuck and I used to plough up some right steep stuff just to annoy the guys who were stuck (I was 18).

Quattro even makes up for lack of visibility too!

They have all moved to Audi

****

If you have that traction the 4x4 will brake better as the engine braking affects all wheels, it will steer better as all wheels are driving and/or pulling it round the corner. Basic mechanics says that a wheel under power is a wheel under control, a free-wheeling wheel is, well a free- wheeling wheel!

Not true.

Our Octavia 4x4 with summer tyres is useless at cornering/stopping compared to our 2wd Mondeo ST with winter tyres.

Not true.

Our Octavia 4x4 with summer tyres is useless at cornering/stopping compared to our 2wd Mondeo ST with winter tyres.

The most important thing is traction (therefore tyres) doesn't matter if you have 2 or 16 WD if you are on summer tyres on sheet ice!

If you have that traction the 4x4 will brake better as the engine braking affects all wheels, it will steer better as all wheels are driving and/or pulling it round the corner. Basic mechanics says that a wheel under power is a wheel under control, a free-wheeling wheel is, well a free- wheeling wheel!

Think of it like this, abs only works if one set of wheels is turning at a different rate to the other set... ie a skid.... Abs won't help you on snow or ice, once all 4 wheels have locked up the abs thinks you've stopped even though you are skidding with all 4 wheels locked over the surface on the ice.

That's funny?! My abs kicked it every time I braked on snow this morning on my way home from work.

That's nice for you...

They have all moved to Audi

****

I bet it's no mistake they blanked out the front number plate but left the rear plate visable

That's funny?! My abs kicked it every time I braked on snow this morning on my way home from work.

I find that ABS is a shile of pite on gravel, snow or ice and wish I could turn it off.

In these instances you want to be able to lock the brakes, so you can build up stuff.

Think of it like this, abs only works if one set of wheels is turning at a different rate to the other set... ie a skid.... Abs won't help you on snow or ice, once all 4 wheels have locked up the abs thinks you've stopped even though you are skidding with all 4 wheels locked over the surface on the ice.

That's not how ABS works.

ABS works primarily on the wheel speed sensor, when the speed reaches zero, the system pulses pressure to maintain rotation just before the onset of wheel lock up. It might compare relative wheels speeds as part of it's control strategy, but that's not how fundamentally it works. ABS "works" on every surface, the problem is that most system cannot differentiate the braking effort between wheels, so the max brake force applied is dependent on the wheel with the lowest grip, which makes sense otherwise you'd be spinning around all over the place. Braking on very low mu surfaces will always be an odd experience, simply because their is so little friction that ABS prevents almost any braking force.

A skid is defined as the point at which the forces on the wheel have exceeded the frictional force between the road surface and the tyre, be it in the rolling direction, or laterally.

The other point to remember in the above is that the coefficient of friction is always greatest just before the onset of a skid - once in a skid then the coefficient (and the resultant braking force) decreases - so ABS actually helps to keep you at the peak point...

On softer surfacese though (ie snow or gravel) there is, however, a definite benefit to building up a wedge of material in front of a locked wheel as this can contribute more to the braking force...

Thank you kind sir for supporting my point.It helps if people read the posts before jumping in feet first

Not true.

Our Octavia 4x4 with summer tyres is useless at cornering/stopping compared to our 2wd Mondeo ST with winter tyres.

Comparing apples and pears there. If you compare like for like are you honestly implying that the 2wd Mondeo on winter tyres would be better that the 4wd Octy on winter tyres?

I don't understand the not clearing snow bit. Snow is a piece of **** to clear off your screen. It's ice that's a bugger. Admittedly I'll leave half an inch or less on the roof because I don't want to scratch my paint but that's easily handled by the wipers.

Comparing apples and pears there. If you compare like for like are you honestly implying that the 2wd Mondeo on winter tyres would be better that the 4wd Octy on winter tyres?

That's not what I said, although I mis-read the quote and I most agree with it.

What I mean is that 2WD with suitable tyres is better than 4WD without.

That's not what I said, although I mis-read the quote and I most agree with it.

What I mean is that 2WD with suitable tyres is better than 4WD without.

The last sentence I will agree with, 'tho your post would have been clearer and in beyter context is you had quoted the 2nd and important paragraph in my original post

" The most important thing is traction (therefore tyres) doesn't matter if you have 2 or 16 WD if you are on summer tyres on sheet ice!"

Edited 22 January, 201313 yr by slider

That's not how ABS works.

ABS works primarily on the wheel speed sensor, when the speed reaches zero, the system pulses pressure to maintain rotation just before the onset of wheel lock up. It might compare relative wheels speeds as part of it's control strategy, but that's not how fundamentally it works. ABS "works" on every surface, the problem is that most system cannot differentiate the braking effort between wheels, so the max brake force applied is dependent on the wheel with the lowest grip, which makes sense otherwise you'd be spinning around all over the place. Braking on very low mu surfaces will always be an odd experience, simply because their is so little friction that ABS prevents almost any braking force.

A skid is defined as the point at which the forces on the wheel have exceeded the frictional force between the road surface and the tyre, be it in the rolling direction, or laterally.

you are missing the point entirely here.. I think you need to read up on how abs works pal... If all 4 wheels have stopped turning and the wheels are skating over the top of the ice, the abs controller thinks the car has stopped so it will do nothing, simple as that.. also there is a speed threshold under which the abs will not function, it varies from car to car but it's circa 15mph.. The point to this whole thing is tractive resistance, obviously if you have grippy tyres it will take longer to break traction than if you have normal summer tyres on because the tractive resistance is higher, but once that threshold has been exceeded the wheels will still lock up.. Yes I admit more modern abs systems incorporate ESP as well which helps because it utilises acceleration sensors to feed it additional info... My fingers have one to sleep now.

For a more complete run down of how all the ABS, ASR, EDL, ESP...etc etc systems work look at my big post here.....

http://www.briskoda....asr-esp-hhcetc/

Clearer info to get your head around!!!

you are missing the point entirely here.. I think you need to read up on how abs works pal... If all 4 wheels have stopped turning and the wheels are skating over the top of the ice, the abs controller thinks the car has stopped so it will do nothing, simple as that.. also there is a speed threshold under which the abs will not function, it varies from car to car but it's circa 15mph.. The point to this whole thing is tractive resistance, obviously if you have grippy tyres it will take longer to break traction than if you have normal summer tyres on because the tractive resistance is higher, but once that threshold has been exceeded the wheels will still lock up.. Yes I admit more modern abs systems incorporate ESP as well which helps because it utilises acceleration sensors to feed it additional info... My fingers have one to sleep now.

I've worked for automotive brake systems manufacturers, so I know how they work, and no need to be patronising thanks.

If all four wheel have stopped rotating, and you are pressing the brake pedal, and the vehicle has ABS fitted, then you can only be stationery. That was my point.

Are they not anti LOCK braking systems because they detect the brakes locking up suddenly?

The ABS controller detects the car is going at 30 mph. Then in half a second all 4 sensors read 0 mph. The ABS will kick in because of the very high declaration detected, not ignore it because all 4 wheels read as stationary.

Are they not anti LOCK braking systems because they detect the brakes locking up suddenly?

The ABS controller detects the car is going at 30 mph. Then in half a second all 4 sensors read 0 mph. The ABS will kick in because of the very high declaration detected, not ignore it because all 4 wheels read as stationary.

Final post on this as this ABS bit is WAYYYYYYY....OFF Topic for this thread..........................

Read my linky above in my previous post re WFT is ABS etc...........

you could in theory hit the brakes and lock all wheels evenly so that they all slow/lock at the same millisecond..............then the brakes will lock and if you keep your foot planted on the brake pedal and the car slides the abs unit will think the car is stationary!!!

In ABS there is only the rotational disc or magnetic reluctor ring which rotates against the fixed pick up sensor in the hub carier to tell that the wheels are rotating..................fool those and there is NOTHING to tell the ABS that the wheels are locked still and yet the car is still moving!!!!!

ABS's job is to make sure that all the four wheels rotate at the same speed when braking......

ESP on the other hand has a " car movement" detector..........(gyroscope)..so this can override the ABS unit and tell it that the car is still moving and tell it to "release" the brakes.......then to pulse them!.....................

Edited 22 January, 201313 yr by fabdavrav

TBH I find all of these aids more of a hindrance than a help in the snow.

ESP gets switched off by me at low speeds for the TC which just causes trouble in snow.

Edited 22 January, 201313 yr by Aspman

TBH I find all of these aids more of a hindrance than a help in the snow.

ESP gets switched off by me at low speeds for the TC which just causes trouble in snow.

You might find that even the manufacturers in the handbook recomend that "when moving off from a stationary position it many be advantageous to disable the ASR/ESP to aid traction on certain snow/gravel surfaces"...........

just look in the cars OEM handbook!...I know mine does for the ASR that I have fitted!....and it is defo better OFF in certain cases...even with winter tyres........but less of a problem compaired to when I had summers on in winter!!!

Out of interest, on a VAG car, can you disable TC (ASR) while keeping ESP on? Every other car I've owned with it let you do this, but I can't remember how my Golf worked it.

ESP is just ASR with knobs on, I don't know if pressing the ESP button completely turns the system off or not.

You might find that even the manufacturers in the handbook recomend that "when moving off from a stationary position it many be advantageous to disable the ASR/ESP to aid traction on certain snow/gravel surfaces"...........

Read the manual! What sort of bloke do you think I am!

I've not spent years breaking things to have to start reading manuals now.

But aye fair point it probably does say that