On the one side A321 neo has almost the same range as the A320 neo (250 NM difference), and a LR version of A321 neo will have an even longer range.

On the other side Boeing 737 MAX line shows a clear tendency: the longer the fuselage the shorter the range. The same tendency can be observed on most aircraft types.

I understand that fuel is generally in the wings which keep the same volume on a stretched derivative, but fuselage can accommodate fuel tanks and range can be a crucial point for aircraft. So why don't/can't aircraft manufacturers propose equivalent range stretched aircraft in general, as the A321 neo does?

On the one side A321 neo has almost the same range as the A320 neo (250 NM difference), and a LR version of A321 neo will have an even longer range. The same goes for the Dassault Falcon 7x and the longer and longer-range Falcon 8x.

On the other side Boeing 737 MAX line shows a clear tendency: the longer the fuselage the shorter the range. The same tendency can be observed on most aircraft types.

I understand that fuel is generally in the wings which keep the same volume on a stretched derivative, but fuselage can accommodate fuel tanks and range can be a crucial point for aircraft. So why don't/can't aircraft manufacturers propose equivalent range stretched aircraft in general, as the A321 neo does?

On the one side A321 neo has the same range as the A320 neo, and a LR version of A321 neo will have an even longer range.

On the other side Boeing 737 MAX line shows a clear tendency: the longer the fuselage the shorter the range. The same tendency can be observed on most aircraft types.

I understand that fuel is generally in the wings which keep the same volume on a stretched derivative, but fuselage can accommodate fuel tanks and range can be a crucial point for aircraft. So why don't/can't aircraft manufacturers propose equivalent range stretched aircraft in general, as the A321 neo does?

On the one side A321 neo has almost the same range as the A320 neo (250 NM difference), and a LR version of A321 neo will have an even longer range.

On the other side Boeing 737 MAX line shows a clear tendency: the longer the fuselage the shorter the range. The same tendency can be observed on most aircraft types.

I understand that fuel is generally in the wings which keep the same volume on a stretched derivative, but fuselage can accommodate fuel tanks and range can be a crucial point for aircraft. So why don't/can't aircraft manufacturers propose equivalent range stretched aircraft in general, as the A321 neo does?