2WD is better in the snow than 4WD - what ?!

[pembo]

Only on one occasion have I ever seen RWD as the better option for grip in dodgy conditions but even then 4WD was just fine.

A very wet and muddy bike race where everyone had to park on a field. At the end of the race everyone loaded up the boots and attached their bikes to the back of their FWD vans and cars. Plenty of them walked past my little BMW 1 series and commented that I would never get out. But when it came to driving away with all that weight over the back wheels I had plenty of traction to trundle out, whilst they all sat there with spinning front wheels (I stopped amd helped push a couple).

[DonkeyApple]

RobM77 said:

Actually, most people living in the alps have normal 2WD cars. We holiday there most years and the lack of 4x4s is very noticeable. Not only that, but we tend to holiday in remote regions with gravel tracks and tiny lanes. Everyone seems to have Yarises and Kas with the odd 2WD 3 series or C Class.

Absolutely but you also have to factor in the economics of such environment also. You will see the same pattern in many such places around the world.

[Jonno02]

Since the driven wheel argument has been done loads, I'll sum it up:

FWD is the devil.
RWD is the devil in the snow.
AWD is the devil until it snows.

[rxe]

Hmmm.

I have a pretty decent Land-Rover Defender. 4WD (of course), air-locking diffs front and back, reasonably gnarly tyres. Pretty much unstoppable, I did get it stuck towing a trailer across a wet field last w/e, but once I'd unhooked the 3.5 tonnes from the back, it had no problem, and I got the trailer out with a winch.

I also have a FWD Alfa 2.5 V6.

Which one do I take out in the snow? Alfa every time. Even without winter tyres, the Alfa is lighter, stops better, doesn't fall off corners. With winter tyres on the Alfa, it really is no contest - it will climb hills that the Land Rover can't, and most importantly, it will stop like a normal car rather than sliding the moment you use the brakes.

I seem to remember 5th gear (or some similar show) took 2 Volkswagens, one 2WD and one 4WD and gradually increased their speed round a wet roundabout - the 4WD fell off the roundabout first because it was heavier.

[Type R Tom]

DonkeyApple said:

Type R Tom said:

Makes you wonder how Eastern Europeans and Russians managed to survive the winters in their Ladas and Moskvitch

They didn't. They died by the bucket load. Even today in modern cars it's still perfectly common to find frozen bodies in stuck cars.

True but I'm just thinking of my own experience as a passenger with a local at the wheel during some awful weather. I would have been driving at single figures, he was not!

[BricktopST205]

When my dad was working out in Poland back in the 80's his breadvan polo went everywhere while a lot of cars were getting stuck in the snow. I think the key here is the makeup of the car rather than its drivetrain.

A small lightweight car on 155 section tyres is going to be a fair bit better than a BMW X5 with its 2+ tonne presence and 285 section tyres.

[DonkeyApple]

Type R Tom said:

DonkeyApple said:

Type R Tom said:

Makes you wonder how Eastern Europeans and Russians managed to survive the winters in their Ladas and Moskvitch

They didn't. They died by the bucket load. Even today in modern cars it's still perfectly common to find frozen bodies in stuck cars.

True but I'm just thinking of my own experience as a passenger with a local at the wheel during some awful weather. I would have been driving at single figures, he was not!

Whether that is down to superior skills or just the cultural cheapness of life could be a debate.

[Balmoral]

Ironically, in the OP, the guy is talking about getting going, which is one of the few areas where 4WD traction will certainly be an advantage over 2WD. I find most folks tend not to know the difference between traction and grip. Grip is exactly the same no matter which wheels are driven.

[RBH58]

Biggest load of nonsense I've ever read.

It's actually quite funny because the reason FWD is more dominant in the USA than RWD is because most people believe FWD is safer and easier to handle in ice and snow.

[KevinCamaroSS]

Balmoral said:

Ironically, in the OP, the guy is talking about getting going, which is one of the few areas where 4WD traction will certainly be an advantage over 2WD. I find most folks tend not to know the difference between traction and grip. Grip is exactly the same no matter which wheels are driven.

Spot on.

[ian2144]

With over 45 years driving experience two of the best cars in the snow by far were the Citroen 2CV and a VW Beetle 1300 on skinny cross ply tyres. Most modern car tyres are far to wide to work well in snow.

[RobM77]

DonkeyApple said:

RobM77 said:

Actually, most people living in the alps have normal 2WD cars. We holiday there most years and the lack of 4x4s is very noticeable. Not only that, but we tend to holiday in remote regions with gravel tracks and tiny lanes. Everyone seems to have Yarises and Kas with the odd 2WD 3 series or C Class.

Absolutely but you also have to factor in the economics of such environment also. You will see the same pattern in many such places around the world.

Oh yes. I wasn't for a second suggesting that a Land Rover on winter tyres wouldn't be better, I was just replying to the comment that people in the Alps drive 4x4s, which is not true.

[Screechmr2]

rxe said:

I seem to remember 5th gear (or some similar show) took 2 Volkswagens, one 2WD and one 4WD and gradually increased their speed round a wet roundabout - the 4WD fell off the roundabout first because it was heavier.

You sure that wasn't in the snow when they tested fwd with winter or snow tyres vs 4wd on summer tyres?

[loose cannon]

DonkeyApple said:

loose cannon said:

Type R Tom said:

Makes you wonder how Eastern Europeans and Russians managed to survive the winters in their Ladas and Moskvitch

Let alone all the U.K. Residents that managed there cortinas etc in the 60's and 70's when we still had snow
I remember my old man battling the snow on the country lanes around Banbury when I was a kid without to much concern
In a marina estate, the trouble today is that people don't no how to drive unless its dry and bright, even a bit of rain today causes kaos on our roads

Marina Estate you say? Are you entirely confident your father just wasn't trying to commit suicide?

Quite possibly though he did pick it off the production line after he had built it I believe,
Hell he even made a profit on it when he sold it several years later

Edited by loose cannon on Thursday 23 February 10:18

[RobM77]

Screechmr2 said:

rxe said:

I seem to remember 5th gear (or some similar show) took 2 Volkswagens, one 2WD and one 4WD and gradually increased their speed round a wet roundabout - the 4WD fell off the roundabout first because it was heavier.

You sure that wasn't in the snow when they tested fwd with winter or snow tyres vs 4wd on summer tyres?

]

VBH did a feature on Fifth Gear on how the three drivetrains respond to constant cornering on a roundabout and in obstacle avoidance (in this case a toy penguin if I remember rightly). However, 4WD isn't intended to improve your cornering speeds - it exists almost solely for the benefit of for traction when accelerating, especially in low weight transfer situations such as snow or wet mud.

[Balmoral]

RobM77 said:

4WD isn't intended to improve your cornering speeds - it exists almost solely for the benefit of for traction when accelerating, especially in low weight transfer situations such as snow or wet mud.

Spot on.

[Pothole]

SS2. said:

When we had heavy snow around here a few years back, BMWs and Mercs were abandoned everywhere - in the middle of roundabouts, on the shallowest of slopes, and with some incapable of even getting their back wheels out of the gutter.

The R32 we had back then was solid as a rock and weaved through the carnage of deserted 2WDs without a care in the world.

If we had similar snowfall again, I know which of the two I'd rather be driving.

Substitute 1998 Volvo S90 for R32 and you'd have my 2WD, RWD experience...it did only run 205s, so narrower than a lot of German stuff.

[Rovnumpty]

rxe said:

Hmmm.

I also have a FWD Alfa 2.5 V6.

Which one do I take out in the snow? Alfa every time. Even without winter tyres, the Alfa is lighter, stops better, doesn't fall off corners. With winter tyres on the Alfa, it really is no contest - it will climb hills that the Land Rover can't, and most importantly, it will stop like a normal car rather than sliding the moment you use the brakes.

Must be the weight of the V6 then, as I had 2 alfas - 1.8 TS and a 1.9 jtdm - on winter tyres that couldn't make it up the hill to my house in heavy frost, never mind any actual snow.

The first one was the reason I got my first 4x4.

Might have been my lack of skill, but been driving fwd cars in the highlands a long time, and the very basic vectra I had at the same time had no issues - on standard tyres!

[RobM77]

Balmoral said:

RobM77 said:

4WD isn't intended to improve your cornering speeds - it exists almost solely for the benefit of for traction when accelerating, especially in low weight transfer situations such as snow or wet mud.

Spot on.

The last point is an important thing that many people forget. Most of us realise that in heavy braking the front brakes do most of the work (in a front engined car the brake balance can be around 70:30 F:R). Hard acceleration is the same, just the other way round: the rear tyres do most of the work. This is why it makes sense for road cars to be rear drive, because on wet or dry tarmac hard acceleration is possible, and the harder you accelerate, the more grip the rears get and the less grip the fronts get - so FWD is a vicious circle and RWD is a virtuous circle.

The problem comes when it snows or when you have wet mud or wet grass, because there's not sufficient grip for a car to accelerate hard, so it's not shifting its weight over the rear wheels in anywhere near the same degree as described above. This means that FE/RWD has a disadvantage, and FE/FWD has an advantage, because in a very low mu situation cars accelerate using their static weight distribution. 4WD is even better in these situations, because all four wheels are driving the car forwards. The problem with 4WD is its weight, complexity and mechanical drag/inefficiency (although the latter is avoided with modern Haldex type systems); it's great if you're in low mu situations a lot, but on wet or dry tarmac where traction is rarely an issue, 4WD is rarely necessary.

Lastly, tyres make a massive difference. The point about the Alps is that 2WD cars are cheaper to buy and run, and with the right tyres, 4WD is rarely actually necessary. Sure, it's better, but with the right tyres, 2WD can be ok.

[RobM77]

Pothole said:

SS2. said:

When we had heavy snow around here a few years back, BMWs and Mercs were abandoned everywhere - in the middle of roundabouts, on the shallowest of slopes, and with some incapable of even getting their back wheels out of the gutter.

The R32 we had back then was solid as a rock and weaved through the carnage of deserted 2WDs without a care in the world.

If we had similar snowfall again, I know which of the two I'd rather be driving.

Substitute 1998 Volvo S90 for R32 and you'd have my 2WD, RWD experience...it did only run 205s, so narrower than a lot of German stuff.

Plus don't forget that traditionally Volvos were FE/RWD, and they're Swedish...

During that heavy snow I was on winter tyres and living in the sticks and I was quite happy with FE/RWD. Sure, 4WD would have been better, but it's not my preference for the other 10-11 months of the year.