It really depends on what you want out of a car. The 2018 Chevrolet Trax has more cargo space and a bigger back seat, and it gets better gas mileage than the 2018 Buick Encore. The 2018 Buick Encore, on the other hand, has better safety ratings, a smoother suspension, and more features inside than the Trax. In the end, it all comes down to what you want and need.