[anibap]

Hi

I have a G20 330i RWD with factory-fitted 19 inch 791M wheels with Adaptive suspension and M Sport Blue callipers (2NH)

Tyres Pirreli PZero RFT in staggered spec 225/40/R19 Fronts and 255/35R19 Rears.

I am quite happy with the setup, as the adaptive suspension does a wonderful job. With larger potholes and bumps, the ride is harsher as the tyre height is too short that even adaptive cannot help (slowing down helps but you can't anticipate potholes at speed or in turns)

I recently did a road trip in France, and the roads were so good that the 19-inch setup was a great experience driving in Sport mode. Unfortunately, the roads in the UK where I live, are not good compared to Europe, with potholes galore. Driving cautiously to avoid potholes dampens the thrill of driving the car to a certain degree.

I am thinking of adding a spare for winter/alps trips (or make it the main set if the ride comfort increases and keep the 19 as spare) to the 18-inch staggered setup with the 790M alloys. I need some help and advice with the following questions, keeping aside the aesthetic advantage of the 19 wheels.

1. Will 18-inch wheels work with the adaptive suspension? or is it optimsed for the 19 wheels from factory?
2. Will the larger Blue callipers work with the 18-inch wheels?
3. I see many owners use an 18-inch setup for winter only. Are there any limitations of using them all year round?
4. Do I need to change anything in tyre settings so that the car adjusts the speedometer to reflect a smaller tyre size?
5. Will there be any noticeable difference in ride quality, comfort and handling with 18 inch moving from a 19 inch?

Anyone who changed from 19 to 18 permanently?

I appreciate your help.

[G22b58]

Some answers:
1. Will 18-inch wheels work with the adaptive suspension? or is it optimsed for the 19 wheels from factory?
Answer: Don't think that makes a difference.
2. Will the larger Blue callipers work with the 18-inch wheels?
Answer: Yes (at least with BMW G2x wheel options). I have 2NH brakes and BMW original 18" (staggered).
3. I see many owners use an 18-inch setup for winter only. Are there any limitations of using them all year round?
Answer: No, thats fine.
4. Do I need to change anything in tyre settings so that the car adjusts the speedometer to reflect a smaller tyre size?
Answer: With the correct tire dimensions for 18", the diameter is practically the same to not significantly change speedometer. But you should input the correct wheel spec when you reset the TPMS settings.

[anibap]

Originally Posted by G22b58

Some answers:
1. Will 18-inch wheels work with the adaptive suspension? or is it optimsed for the 19 wheels from factory?
Answer: Don't think that makes a difference.
2. Will the larger Blue callipers work with the 18-inch wheels?
Answer: Yes (at least with BMW G2x wheel options). I have 2NH brakes and BMW original 18" (staggered).
3. I see many owners use an 18-inch setup for winter only. Are there any limitations of using them all year round?
Answer: No, thats fine.
4. Do I need to change anything in tyre settings so that the car adjusts the speedometer to reflect a smaller tyre size?
Answer: With the correct tire dimensions for 18", the diameter is practically the same to not significantly change speedometer. But you should input the correct wheel spec when you reset the TPMS settings.

Thanks a bunch for clarifying my questions. Much appreciated.