A straight-twin engine, also called an inline-twin or parallel-twin, is a two-cylinder setup where both cylinders sit side by side, upright, and share a single crankshaft. It's the simplest way to ...

Although Subaru didn't invent flat engines, and isn't the only automaker still using them, those motors have become a defining characteristic of the brand. (The same can be said for all-wheel drive, ...