Z4 Roadster Impressions on an asphalt canvas. Whether you opt for 255 horsepower in the Z4 sDrive30i or find yourself upgrading to 300 horsepower in the Z4 sDrive35i, you'll get to enjoy all the BMW performance with the top down and the wind through your hair. For a full list of features and options, contact a BMW Internet Sales Consultant today for a test drive!