I avoid Shell fuel like the plague, every time I've had to use it over the years I've regretted it... pinging, surging, bad economy, frankly I don't know how the company is still in business, obviously most users are oblivious to what their car is doing, or just don't know any better? Or maybe I've just been unlucky enough to get a bad batch EVERY TIME?
These days I will drive out of my way to use BP Ultimate, or Caltex 98 in a pinch.
Also, if your car sits around between drives for any length of time you should stay clear of any ethanol content if possible, unless you're able to drain and flush the system with straight petrol before storage. Ethanol is hygroscopic (meaning it absorbs moisture), which is not that big a problem unless the fuel sits around for any length of time, then the moisture causes the ethanol to separate from the fuel it was suspended in, making it settle to the bottom of the tank with the petrol floating on top.