PHOENIX — For BMW enthusiasts, there’s no car more epochal than the 5 Series. It was first introduced by the German automaker in 1972 and is now in its seventh generation. Called the G30 in BMW parlance (the original 1972 model was known as the E12), the mid-sized sports sedan has grown and is slightly longer, wider and taller than the previous F10 generation (2010-2016), yet sheds 137 pounds thanks to the extensive use of aluminum, magnesium and high-strength steel.