Significant lack of grip & traction - thoughts!?

I was going to say that Cross Climates aren't the stickiest of rubber. we have them on the XC90 and its not rare for it to go a bit sideways but that's me messing around on roundabouts not at 20MPH.

I've no idea what could cause such low speed traction issues apart from road conditions like ice and diesel. Check the insides of the tyre. I had a massive shock with the 911 the other day. The outer edges of the tyres had about 6mm of life while the inner edges were worn down to the canvass.

Interestingly the diff was checked when the driveshafts etc were replaced as there is a 'clunk' when the driveline is under load (or off load - like a metallic clunk when you come on / off power even at very low throttle loads - including idling).

However, it was opened up and inspected and no issues were found (apparently it looked like new!) but that is something I'm slightly concerned about. I am almost certain the issue with the noise is related to the diff input flange which appears to be a common problem with BMW's of a certain age as it dries out and needs to be repacked with grease which I absolutely need to get done but I don't think it is causing this grip issue.

I'll have access back to the shed soon (only a couple of tons of rubble in the way right now) and will probably bite the bullet, get new summer tyres fitted to the other rims and see if that helps. My reluctance is purely financial as the house has taken every last penny (and more) but also as once things are settled I will start looking for a replacement - this was only intended to be a stop gap car!

I presume the diff is an open one and not an LSD. Normally unless there is serious wear or something is broken an open diff wouldn't have the impact described.

I've got CC+ on the Golf at the moment and grip has never been an issue. They can take a full bore start in the wet despite this being their 4th winter on the car.

I think they are a perfect winter tyre for the UK.

Just another thought, were the new driveshafts specifically for your car or just a generic 1 series? There might be a small difference in length.

Bushes have been checked for play and nothing apparent but I will get the garage to double check all the diff mountings etc when it goes in for further investigation (The driveshaft center support bearing / guibo thingamy was also changed initially as that is a common cause of 'clunk' but alas no joy)

I think this might be the issue but as with most things it costs to rule out problems and feels like we started with the wrong thing (though shocks and shafts needed replacing anyway so not a big issue)! 

bmwrepairguide.com/sib/330408.pdf

No LSD?

With all the building work going on at your house, could the tyres have been contaminated / damaged by some chemicals in use? Something like a silicone spray or lubricant or something that has hardened the rubber?

P Zero (the PZ3 version I suspect we are talking about) definitely have issues as they age, I think its time as much as wear/mileage. My car was like one of those "what happens if you put budgets on the rear of a sports car" Youtube vids when I bought it. And they were not the only tyres I have ditched on the rear of a powerful car well before the tread was illegal - the last set of winters were binned with 5mm on them, they just quite suddenly lacked any grip at all to a frankly dangerous level - but they had done 5 winters (of probably 6k miles a time) so fair enough.

Also at this time of year Clunes I find grip is low, full stop, even on roads that look dry. I had a trip in the Jag recently in about 8 degrees, dry but damp, where the whole (gently driven) journey I just didn't feel the grip was there. I decided it must be in my head then had a fair moment - loss of front then also rear - at a junction, again at sensible speeds. I find winter tyres just do this sometimes, I'm always wary on them. But the next day I drove the Boxster and had a massive bite of oversteer at truly pedestrian speeds, pulling out of a junction when someone let me out. I was looking left and waving thanks with one hand, and caught it with the other, there's one person who'll never let a Porsche out of a junction again as I assume he thought I did it deliberately! I wish. So that's two different cars, one on winters one on summers, causing issues in supposedly tame conditions and hoinestly I was not pressing on my any standards. 

When I was a yoof I had plenty of little slippy incidents in the winter, trying to drive like I did in the summer - as you age you realise you need to watch it in the winter, especially with RWD. And worn tyres are much the same, they just don't work the same. The Jag winter fronts have 4-5mm on them, but have done all 7 XFR winters I have had, they are now pants and will be chucked in the autumn... It can seem like bad economics to bin a tyre that's still highly legal, but they can be safety issues and ruin your enjoyment of your car, which is worth investing to avoid!

You’re supposed to change winter tyres at 4mm if that makes you feel better!

I changed the summer tyres on the Golf at 4-5mm because I was fed up waiting for them to wear out so I could put a set of PS4S on the car.  I’m glad I did, the difference was noticeable which isn’t always the case when you spend money on a car.

Crossclimates only have just over 6mm when new !
The Fiesta was MoT'd 40 miles after I had the new tyres put on, and that's what the report said

It might just be certain tyres and greasy roads causing this.

I had a significant slide last night coming off a roundabout while in commuter traffic and DEFINITELY not trying.
It was 8 degrees and I was in the BMW with full winters (Continentals) on.

Fortunately a bit of accidental Qweefesque opposite lockery saved the day as the DSC was clearly fast asleep.

Tyre depth on service reports you can usually ignore - I have had many a new tyre under-reported and sometimes they mysteriously grow tread depth over a year Plus my spare tyre is usually in great condition - especially on cars that don't have one..............

"UUHP" tyres (like BS Potenza Sport and the ubiquitous PS4S - not to be confused with the PS4 - often do have as little as 6.7mm on them new. They grip like shit to a blanket though, which means you can invest your way to grip if you like. I don't think it's fair tarnishing all of a brand's tyres with the same brush, the PS4 P Zero is much better reported than the PS3 for example, and Bridgestone did nothing much in the UHP or UUHP world until the recent Potenza Sport, and has a generally very good lineup now having launched a lot of new models in the last 3 years. Even the runflats are supposed to be much better. It's a bit odd how tyres of the same model are sold for so long, you need to do your research - I suppose when the production lines are up, you keep going while people buy them...

Having just done a few thousand km in Bavaria in a nearly new X2 with Sottozero 3's on it, which felt nailed down the whole time and handled even wet sheet ice in a car park fine despite being only FWD - I wonder how much we suffer here from our combination of crappy roads, heavy traffic (so more chance of small spills of diesel and so on), and extremely variable weather.

Clunes, have you got to the bottom of this yet and found the cause?