I believe gas is gas.
Here in Atlanta I use Costco Kirkland Signature Premium. Zero problems.
In fact zero problems with the other four previous BMWs we've had.
On the road I tend to use Shell 93, or Chevron. I look for busy stations (fresh gas) and high fuel fill rates (clean filters).
Character does count. For too long we have gotten by in a society that says the only thing right is to get by and the only thing wrong is to get caught. Character is doing what's right when nobody is looking... " --J. C. Watts