Ice on Tarmac - 4x4?

I've been reading that we shouldn't drive the Jimny on 4x4 when on tarmac, does this include tarmac covered in ice or black ice?

The missus is obsessed with having it in 4x4, just because it has it & we previously looked at a permanant 4x4.

Can someone giver her a good answer please?

She won't believe me!

I have had it slide out on me in 2WD though, so i can see her point.

I ain't no expert, but id say that as long as its all ice (like a road thats covered at least 80% ice/slush etc) then i would think it would be ok. just have to remember that just because its 4WD doesn't mean it wont still slide out on you again - speeds and braking distances whilst on ice in particular still have to be reduced and increased by a factor of ten respectively.

Saying that - if the road is only partially covered in ice, and theres periods of good grip and or bends with no ice - then you could be opening yourself up to ''transmission wind up'' if unnecessarily using 4WD- read the hundreds of threads on here about the EXPENSIVE consequences of breaking CV joints and the like - So that has to be kept in mind too.

I know i haven't really properly answered your question definitively, I'm just sharing what goes through my mind when i press the 4WD button... Hope it helps.

Cheers Andy.

I'm just reading up as much as i can.

Never had a 4x4 before, now I have to try to explain transmission windup to the mrs!!

Lol.

That's after I've worked it out myself. All wheels go at same speed, making it harder to turn on "grippy" surfaces...is my take on it.

Nice one pal.

theres a good reply on here somewhere to a thread by martin i think, explaining that when in 4WD all the wheels are effectively jointed together - so all need to turn at the same speed and run the same distance over the ground to do so. if you try to turn on a grippy surface, the outer wheels will turn further that the inner wheels (relative to the turn circle) and thus won't turn at the same speed - causing major internal problems and breakages

Lol, just read that one.

Makes more sense now, as I said...

Complete Noob.

Dont forget though ... even in 4WD, you still have open diffs front and back, so you will have a degree of control .. its not an absolute No no to put it into 4x4 while on tarmac, just donot go turning lock to lock ( risk of transmission windup)

last year I was offroading on sheet ice and I was in 4x4. this made no difference what so ever ... I even attempted to tow a friend who was also in a 4x4 and had become stuck with 2 wheels on the ice, 2 wheels on a grass verge ... together we were both going no where.

I wouldnt advise driving any distance in 4x4 if the conditions donot warrent powering all 4 wheels, but IF conditions dictate, and you need that little extra condidence, then use it.

Good description of Windup is here..
www.pps.net.au/4wdencounter/4wdtech/vehicle_features.html