I6 (as well as boxer engines and I12s) offer perfect primary and secondary balance, making them smooth as a baby's bottom. Make it a diesel and you literally have the perfect touring motor ever (think big rig engines; made for mileage, efficiency, and torque). Heck BMW already has the technology! Imagine a Busa-buster that uses the engine from their 335d! twin-turbocharged 3.0-litre inline six anyone?better than a 90 degree Little Bang V4?