Airbus 319-100 vs Airbus 321-100

[PSW]

Why is the Airbus 319 has less range than Airbus 321 when they both have almost the same engines ?

[microlight]

Could be somethig to do with the speed and altitude - the bigger A321 is slower and lower (around M0.74@FL360 max) than the A319 (around M0.82@FL390 max). Faster = more fuel burnt, so less range? Just a theory!

[Nexus]

I think that it all comes down to engine power.
The A319/320/321 all use the General Electric/Snecma CFM56-5B

The 5b family also has different types, like the 5B2, 5B4 etc. The difference is raw power basically. The engines for the A321 has better Max. climb thrust than the others, for example...

Airbus 321 uses the CFM56-5B1 and 5B2

Airbus 320 has the CFM56-5B4

Airbus A319 is equipped with CFM56-5B5, -5B6