What is a BONDI engine?

What all is included in engine tuning(building, not modifiying)?

• What exactly is involved in engine tuning(engine building)? I know that cylinder bore, engine rpm and compression is related to power, as is the air/fuel ratio and what-not. I also know that crankshaft stroke, compression and air/fuel ratio is related to torque. however, I am curious as to what else determines things such as horsepower, torque and fuel economy. In examples a 2.0 liter engine with a 5spd manual transmission can get 130 hp and 135 ft-lbs tq and 33 mpg highway where as a 4.6 liter engine with a 5spd manual transmission can get 260 hp and 302 ft-lbs tq and 25 mpg. I would expect the mpg to go down because the engine is bigger and had more power but a 5.7 liter engine and a 6spd manual transmission can get 350 hp and 365 ft-lbs tq and 29 mpg highway. That last one is what baffles me, though that last one is 1.1 liters bigger in displacement than the 4.6, it gets more gas milage, almost as much as the first engine, though it is 3.7 liters bigger. Why is this?

• Answer:

  The most important thing you need to realize is that gas milage is not only effected by the engine, but also by the vehicle itself. The weight of the vehicle affects the gas milage, as does the aerodynamics of the vehicle.