quote: Having twin turbos vs. single turbo will not increase power. It'll just improve spool time.
quote: Sequential configurations also allows variable boost while cruising because you can have a dual-stage wastegate that will reconfigure the boost path. This means while cruising at low-rpm, the small turbo could be completely bypassed and the larger, quieter turbo could continuously feed a regulated ~5psi, something that can't be done in a single turbo application where efficiency is wasted by over boosting at highway RPM.
quote: They therefore have variable boost.
quote: The cylinder size has increased slightly and if bore were increased as well it help retain the max torque figure; likely at the cost of usable rev range
quote: Changes to the fuel injection system could explain a high max. power, whilst also allowing considerably improved cruising mpg (further helped by the reduction in capacity)
quote: The main point being that the traditional methods of implementing internal combustion engines in vehicles is highly inefficient. Historically this is limited by a need to make engines mechanically self-regulating.