Why the engine capacity of diesel is 1047cc instead of petrol 1199cc. Whether the pick up at village turning elbow with ac be ok or ac has to be turn off at turning elbow bends

@SVP Why the engine capacity of diesel is 1047cc instead of petrol 1199cc. Whether the pick up at village turning elbow with ac be ok or ac has to be turn off at turning elbow bends.

Question asked from: http://www.carandbike.com/tata-cars/tiago