Boba

I wouldn’t say things like ‘can only’ though. My last car was a 2017 G31 520d ex demonstrator and came with the standard mSport larger brakes and 19” staggered wheels. I agree it’s less likely though I notice the OP is on 19”.

Mine too - Goodyear RoFs - seem to perform well. Like the OP I have 19” summers but it was cheaper to buy 18” wheels and tyres for winter than just 19” tyres and less hassle too.

The Carly app is ridiculously expensive though with an annual subscription equivalent to an all-time purchase of other tools and few additional features.

It’s common for cars to come from the manufacturer with a different size of spare wheel. My last omega had a skinny 17” spare and 18” wheels as standard. Labelled for restricted speed but never needed it I’m glad to say. FWIW a wheel with a well-worn but legal tyre could be a cm less in diameter than a new one on the same axle and I assume the car could cope with that if it had to. Why do you think the xDrive would be different?

Why are all these pouches so huge? Even the display key doesn’t need that size. (My display key lives in the safe indoors anyway as it’s too big to be of any practical use and it’s battery is always flat any time I look at it).

You’re not driving quickly enough!

This was discussed earlier in the thread (see @Matthew Ashton). As I said earlier I always fit winters November to March, done it for years. The question was more about what ambient temperature the real benefits are seen at and whether it varies as the tyre temperature rises.

it’s interesting in a small way as I’ve noticed that the pressures recommended on the status screen also varies (as it should) with tyre temperature and actual pressures.

Yes I wondered about that but it’s not only the point of contact I believe but the whole flexibility of the tread pattern that matters. I’d guess that the rubber temperature varies through the tyre from whatever the TPM sensor can see to whatever the ambient is, so it’s not quite as simple as saying it’s only the temperature of the road surface that matters. And as I said, it’s not mentioned in tyre tests where they’ve not done many miles. Not disagreeing that winters are better overall just now, it’s why I use them, just chewing the fat and as I’m a physicist interested in it.

Yes this is all fundamental, well-documented stuff but it’s not what I’m interested in. My point is that after a relatively short drive my TPMS reported temperatures well above the point at which winter tyre compounds and treads offer these features, and so my question is whether the advantages are still there when the tyre temperature is so high even when the ambient temperature is low. As far as I’m aware all of the figures quoted and demonstrations given are with the tyres at or near to (low-temperature) ambient. Naturally the tread gives better winter traction and steering in snow than clogged-up summer treads but that’s a different question. @Mr H my TPMS displays tyre temperature and pressure on the vehicle status screen. I can’t remember now whether it was an iDrive-selectable option or whether I coded it, sorry, but the data is available one way or the other.

After just 10 shifts? Mine has shifted to 5th or 6th and back to 1st by the time I’m at the junction at the end of the road quarter of a mile away. Doesn’t sound much of an issue?

You probably left it unlocked or just as likely fell victim to the well-known problem of accidentally pushing key buttons in your pocket by bending or sitting down. It’s usually my boot lid I find standing open. Damn annoying.

I use winter tyres because it’s not uncommon to get snow here in Scotland - it’s only a few years since we had over a foot for over a month and we had a JCB out to clear our culdesac. I was more interested in whether they’re as effective when they’re so much warmer and roads are only wet or icy. Just ruminating really as I always change anyway. As a bit of an aside when we had the JCB the guy piled the snow on the pavement at the end opposite the culdesac and it made a heap about 8 feet high and 12 feet diameter and froze solid. 2 days later a water main froze and burst along the road and guess where the stop valve turned out to be?

Yes I do understand that, it’s why I always change tyres in November and March, but what I’m saying is that according to my TPMS my tyre temperatures after a relatively short run were far above the 7 degrees that’s supposed to be the changeover point so are the winters still effective at that temperature or are they even safer than the summers would have been? Presumably the tyre testing is done with tyres at ambient?

I’m not sure how general a remark that is. Both my last Ford and Vauxhall needed to have map updates bought from the beginning (not after 3 years). My Omega even had map key protection built in to prevent bootleg updates from killing off the lucrative after sales.