When it comes to choosing your all-new Sonata, you'll be faced with 3 powertrain choices. So how do you decide which one is right for you? I've already driven the 2.4 and 2.0T engines and now I complete the trifecta with a week in the gas sipping Sonata Eco. Sandwiched smackdab in the middle of the new Sonata lineup sits the Eco. Now depending on which of the 6 models …