Diluting Your Brand or Competing and Growing Your Market Share?

Both BMW and Mercedes Benz are known for their terrific high-end performance cars. I know that since I own one of them. They have not been recognized for their emphasis on fuel consumption technology. But that’s about to change soon when both companies are about to reveal new car models offering better fuel consumption. So what do you think? Is this an attempt to enter emerging new markets such as India and China and compete against other brands and/or possibly show their concern for the environment? If they are successful, would this move dilute their brand for their high-end driving machines?