[Rich9600]

Hey guys. I fitted my winter tyres just over a week ago and so far I've used them at air temperatures between 4C and 15C in dry, damp and wet conditions.

I opted for the insurance safe BMW approved setup, but have staggered 441M wheels shod with Pirelli 225/45/R18 V (*) runflats all round.

I've been impressed with the 'eager to turn nature' of a square tyre setup compared to my staggered summers. However, the back end is a touch looser under power... The car also feels a little twitchy at speed compared to the staggered summers. Possibly a feature of moving the centre of grip forwards due to relatively less rear grip.

The higher aspect ratio has somewhat blunted the sharpness of the turn in and there seems to be more body roll. Possibly due to greater sidewall flex.

Ride quality is not significantly changed, though I'd say the Pirelli winters are quieter than Bridgestone summers.

The tyres perform excellently in the wet and judging by the spry in my mirror shift a lot of water. On damp warm roads they are also excellent. I drove on a flowing twisty damp road today and enjoyed myself. My Bridgestone summers were getting a touch twitchy under similar conditions previously. So, in the damp even at 10C I'd judge that the winters are already showing gains.

On bone dry roads above 10C the summers still have the edge. However, the Pirellis are still perfectly fine.

Overall, I'd rate the Pirelli Sottozero as a good tyre to fit under summer/winter crossover conditions. I think they will be very well suited to the cold wet and windy weather that seems to be the reliable feature of a British winter. Though, I'm kind of looking forward to some properly cold winter weather to play with.

[evan15281]

my Yokohama W drive winters (18 inch) are a little noiser than my 19 inch goodyear eagle F1 summers.

Don't know if I'm surprised or not.

[Nick the Greek]

The staggered set up turns in fine, if you drive it correctly...

Continue braking right up to the apex, this will load the front wheels and "loosen" the rear.

As you get to the apex, get back on the gas.

You will feel the car "pivot" as it turns and the front end dives for the apex.

[HighlandPete]

Originally Posted by Rich9600

I opted for the insurance safe BMW approved setup, but have staggered 441M wheels shod with Pirelli 225/45/R18 V (*) runflats all round.


Ride quality is not significantly changed, though I'd say the Pirelli winters are quieter than Bridgestone summers.

You've fitted 225 section on your rear staggered setup? That could be one reason for the different and slightly twitchy feel. A tyre with less lateral movement on the wider rim will likely move about a bit more as it will be less able to follow the road contours. It can be a similar reaction when we have different tyre brands/specification front to rear on our BMWs.

I used to change from a staggered set to a square setup for winter on my 330d, no issue with any twitchy behaviour. In fact the square setup with summer or winter tyres was the better balanced chassis, neutral handling and better turn in, the staggered setup turned the car to slight understeer.

We expect a bit of difference in ride quality. I fitted my winter wheels on Friday and I'm down a rim size, winter run-flats are smoother riding on the 5-series at current ambient temperatures and running cold tyres. For me they feel like the summer set on a hot day and with the tyres running warm. I notice how the summer's start to harden up on colder days and they just don't heat up in wet conditions.

HighlandPete

[Rich9600]

Originally Posted by HighlandPete

You've fitted 225 section on your rear staggered setup? That could be one reason for the different and slightly twitchy feel. A tyre with less lateral movement on the wider rim will likely move about a bit more as it will be less able to follow the road contours. It can be a similar reaction when we have different tyre brands/specification front to rear on our BMWs.

I used to change from a staggered set to a square setup for winter on my 330d, no issue with any twitchy behaviour. In fact the square setup with summer or winter tyres was the better balanced chassis, neutral handling and better turn in, the staggered setup turned the car to slight understeer.

We expect a bit of difference in ride quality. I fitted my winter wheels on Friday and I'm down a rim size, winter run-flats are smoother riding on the 5-series at current ambient temperatures and running cold tyres. For me they feel like the summer set on a hot day and with the tyres running warm. I notice how the summer's start to harden up on colder days and they just don't heat up in wet conditions.

HighlandPete

All very true. The Pirelli 225's are rated for 7J-9J rims. So 8J and 8.5J are well within spec. Front and rear tyres both project beyond the rim, though there is a visible difference. So, as you suggest I would expect slightly different behaviour.

Thinking on, I set my tyre pressures at 5C and it was 12C today... So, possibly running a little hard also. Front 2.8 and rear 3.0 Bar. Summers are 2.6 all round.

Twitchy is probably a poor description. It feels more like my E90 SE at speed. Not unstable in any way. Just not quite as solid as I've become accustomed to on my F30.