A V16 engine is a V engine with 16 cylinders. Engines of this number of cylinders are uncommon in automotive use. A V16 engine is perfectly balanced regardless of the V angle without requiring contra-rotating balancing shafts which are necessary to balance engines with odd numbers of cylinders in-line or those equipped with counterweighted crankshafts like the 90° V8. In addition V angles of 45° and 135° give an impulse every 45°, so are optimal solutions, for even-firing and non-split bearing crankshaft journals.