Tyre pressures

[Lanterne Rouge]

What does anyone else make of the decision by ALPINA/BMW to re-set the default recommended tyre pressures on all B3/D3 20” wheels permanently to 3.4 bar? I only found out by accident when the latest Remote Software Upgrade to my car automatically changed the figures, resulting in the car warning light telling me I was running on deflated tyres at the old recommended pressure of 2.8 bar for sub-250 kph speeds. I’m told it’s because too many owners in Germany are ruining their tyres by running at max speed on the autobahn at too low pressures, but it’s bloody irritating having to run around our pothole-ridden local UK roads on the higher pressures.

[JohnW]

Not great, as different tyres of the same size perform differently sometimes to a slightly tweaked pressure. Also different pressures within tolerances suit different types of driving and conditions.

[Grumpyjohn1957]

Irritating for sure, all done by nanny for reasons of comfort & safety. At least you can still input your own settings via the iDrive.
I'm sure there'll be an OTA along shortly that permanently locks the speed limiter to 72mph and restricts the throttle opening to 60%.
What's happened to personal responsibility?

[440]

The pressure on my tyres is 3.1 bar. I want to think the higher pressure will protect the wheel from damaging if I hit a pothole. I do not mind replacing a tyre, but I really would not like a damaged wheel. If the roads were in a decent state I would definitely set a lower pressure.

[Jonnywishbone]

I’ve run mine at 2.8 bar since new. I had two punctures last year, one due to a pothole and the other due to a nail as well as a third tyre turning to scrap due to a sidewall bulge of unknown cause but probably due to a pothole. That adds up with the OEM tyres! I’d like to think the forged wheels are a lot less likely to buckle than cast but who knows? I have also begun to suspect over time that the OEM Pirelli’s are trash, even if they are “bespoke” and I’ll probably replace them with Michelins when the time comes.

In any case Sytner inflated my tyres to 3.2 bar at routine service last month. If I’d known I’d have taken some air out instantly but I didn’t and as it happens the car feels quite a bit sharper to drive with better turn in but with no noticeable increase in crashiness over potholes - and my local neighbourhood could easily be twinned with the moon when it comes to the surface texture. I don’t know if the fact that the 30 ratio tyres are so low in profile that the pressures make relatively less difference to ride quality or if it’s just in my head. Or my arse is numb and I just have no feel.

In any case I’m pretty sure I’ll be leaving the pressures as they are.

[Saracenus]

Were any OTA Update release notes published that advertised the pressure recommendation changes prior to upgrading the software?

I’m not suggesting I’d have skipped the update - just that it would have been nice to have been forewarned about this “enhancement.” I seem to remember reading something about general optimisations but nothing about this.

[Sab]

I would ignore these new defaults and stick to the original tyre pressures recommended by Alpina as these were the ones based on there R&D.

I wrote a to them to obtain the two sets or tyre pressures as my car is a 1995 model.

They provided both settings.
Upto 100kph
Over 100kph

[hotentot]

At the Alpina drive day event, a technician from Pirelli said that I can safely drive with a pressure of around 3 bar without affecting the tire life. It was during a less formal conversation. At lower pressure, I notice a slightly more comfortable ride (20 forged wheels).