For the foreseeable future, the LaCrosse will remain the flagship of the Buick lineup, so at first glance, it might seem peculiar that General Motors is adding a seemingly modest inline-four cylinder engine to the sedan’s powertrain list. However, at the time the LaCrosse was being developed in 2007-2008, gasoline prices in the United States had spiked to their highest levels ever, topping $4 per