You say that the gap is perfect because he increased the tire diameter, which means:
1. Has a lower gap between wheels and fenders
2. It raise the car a bit
3. Make the car a bit slower (taller gears)
4. Add more confort (due to the higher tire wall)
5. The speedometer will read less than with oem tires.


Tires.....................Overall Diameter..............Max Load
245/40-18......................25.7"..................... ....730kg___(M-tech Package)

245/35-19......................25.8"..................... ....650kg____(Front Tires)
245/40-19......................26.7"..................... ....750kg

275/30-19......................25.7"..................... ....710kg____(Rear Tires)
285/35-19......................26.9"..................... ....775kg.........(M5/M6)

I personally think that for the non-M5, the best choise is 245/35-19 and 275/30-19 with lowering springs. You don't bought a cheap car, so don't go by the cheapest way.

 

I still have vibration throughout the car. It is less than before, but why buy a nice car to deal with the inconvenience of the whole thing. The BMW is much stiffer than any car I have ever owned, and the 19" wheels will let you feel the road even more, but I think that some of the extra noise in the car is due to the wheels. There is either still a hubcentric fit issue, or the wheels are simply not up to spec. I still have not figured out the answer (although a Hunter machine is telling me my wheels are perfectly balanced and round). I am hoping that maybe the rear strut (which has been recalled) may be causing some of the weird feelings. Or, maybe the steering sensor.
I have an appointment on Thursday with the dealer, and of course, I need to be careful with replica wheels and warranties. All of these issues are not worth the small savings.

Best,

 

If there is no rubbing, why do we have to lower the springs to increase ride uncomfort? I don't have problem wit #5 because BMW odometer overread the speed by 3mph, so if the speedometer read less than OEM tires, it compensate the overread.

I'm not sure what do you mean by "go by the cheapest way". The cheapest way is buying replica 166 and some cheap brand tires.