Traction control or 4x4 in ice and snow?

Strider590

Geotherm wrote: »

Would use the X-Trail, but with winter tyres on. Have a 1992 Mitsubishi Pajero LWB here in Italy. We have to have winter tyres on after certain dates, or carry snow chains as well, otherwise fines are heavy!! Pajero, with its combination of drive formats, can usually cope with virtualy all situations. Citroen, even with winter tyres often needs chains fitted in the snow.
One of the best small cars here is the Fiat Panda 4x4.

Or, how about this!!!
http://autotraderblog.co.uk/2009/12/30/subaru-impreza-pulls-lorry-out-of-snow/

Tyre's = Big difference

http://www.youtube.com/watch?v=dzfZuOTRBD4


Friend of mine insisted he needed 4wd due to the snow 2 years ago, he went out and got an Impreza, then next winter guess what happened?

lovesgshp

Strider590 wrote: »

Tyre's = Big difference

http://www.youtube.com/watch?v=dzfZuOTRBD4


Friend of mine insisted he needed 4wd due to the snow 2 years ago, he went out and got an Impreza, then next winter guess what happened?

Very true, we have to have at least 4mm on winter tyres here. Have just ordered new set as old ones too low!! £600.........:eek:

glasgowdan

As long as you know how to drive in these conditions both would be perfectly safe. Low revs, very low (barely moving) revs or just on tickover if you start skidding. I despair when I see the way 80% of drivers drive in the ice.

mikey72

glasgowdan wrote: »

As long as you know how to drive in these conditions both would be perfectly safe. Low revs, very low (barely moving) revs or just on tickover if you start skidding. I despair when I see the way 80% of drivers drive in the ice.

But it's far easier to use the right car with the right tyres on, and drive normally, rather than prat about like an ice skater in slippers.

DTDfanBoy

Gloomendoom wrote: »

Hmmm... The Kia Sportage 4x4 has an AWD badge on the front wing. It also has a centre diff lock.

The exception that proves the rule?

Not at all, considering it doesn't even have a central diff to lock, I think it simply proves the rule

Flearoy

How about this? Heard they're a bit thirsty and you need a fair size parking space though.

Gloomendoom

DTDfanBoy wrote: »

Not at all, considering it doesn't even have a central diff to lock, I think it simply proves the rule

You are splitting hairs. It has the modern equivalent of a centre diff in the form of a viscous coupling, just like in the transfer box of a 1990's Range Rover... but, unlike the Range Rover, it can be locked to send the drive to the front and rear axles with a fixed 50/50 torque split.

scheming_gypsy

Strider590 wrote: »

Tyre's = Big difference

http://www.youtube.com/watch?v=dzfZuOTRBD4


Friend of mine insisted he needed 4wd due to the snow 2 years ago, he went out and got an Impreza, then next winter guess what happened?

he was doing it wrong http://www.youtube.com/watch?v=O6yj7kHHg08

epninety

Gloomendoom wrote: »

You are splitting hairs. It has the modern equivalent of a centre diff in the form of a viscous coupling, just like in the transfer box of a 1990's Range Rover... but, unlike the Range Rover, it can be locked to send the drive to the front and rear axles with a fixed 50/50 torque split.

My turn to be picky, but it's not really splitting hairs IMV.

The Kia has a controlled clutch pack taking the place of a differential - under computer control it can feed more or less torque to the rear wheels. (As far as I can tell, there seems to be a dearth of technical detail in all the advertising blurb)

The 90s Range Rover uses the viscous coupling (which is very similar to the clutch pack as you say) to limit the slip of a real mechanical centre differential. It's actually connected across the outputs of the centre diff, not just splitting the propshaft.

Without driver intervention, the Kia might be better at driving stability on uneven traction, but the Range Rover will get moving more easily when all four wheels are on slippery surfaces, due to not requiring any wheel slip to set up the system. That's why the Kia requires a manual centre 'diff' lock control.

Gloomendoom

OK, I'll admit I guessed at what looked like a viscous coupling in the Sportage but you are right, a clutch pack makes more sense given the way KIA claims the system works, reacting to feedback from the wheel sensors, and the fact that it can be locked solid when necessary. So, a better analogy than the Range Rover would be any traditional part time 4x4 where the simple in/out dog clutch has been replaced by variable slip clutch that allows the vehicle to automatically share the drive from 100% to the front axle to 50/50(ish) to both axles, as required, on hard or soft surfaces without risking the perils of wind up.