Complex sentence: The Packard inline eight, despite being a very long-in-the-tooth design that lacked the power of Cadillac's engines, was very smooth and combined with an Ultramatic transmission, made for a nearly noiseless interior on the road.
Split into simpler sentences: The Packard inline eight, despite being an older design that lacked the power of Cadillac's engines, was very smooth. When combined with an Ultramatic transmission, the drivetrain made for a nearly quiet and smooth experience on the road.