Oil recommendations

[Center4Ants]

Hi folks,

Brand new here, looking for oil recommendations for my 2007 Z4 Roadster (3.0i), it has 125k miles but I only put on ~5k miles a year.

Some of the options I'm looking at:

• LIQUI MOLY HighTech Full Synthetic 5W-40 Motor Oil (I like the sound of "reduces oil & fuel consumption")
  Mobil 1 High Mileage Full Synthetic Motor Oil 5W-30

Also, given my low annual mileage, should I be changing the oil based on mileage or based on time (like every 6 months)?

Appreciate any help I can get!