Comparing A320 and A319 take off performance
 

Just a question, considering a 60T tow and a runway of 3000m. Standard weather conditions, how much a320 take off performance (flex and vspeeds) are different compared to A319 performance at the same conditions?

Depends on engines...

There is no difference in the wing, so at the same weight there really shouldn't be any difference? Just my assumption. And if I'm not mistaken the braking system, I.e. tire and brakes, are the same so stopping distance shouldn't really matter either.
The 319 has slightly less powerful engines (unless your Bhutan airways) so you might see a lower flex temp, but the thrust would end up being the same.
319 has a slightly larger rudder But slightly higher Vmca speeds at certain alts and Configs (one or two knots difference) but they shouldn't really make a difference at those weights, they star to get limiting at very low V1s (111 knots and below).
Interesting question though, unfortunately I don't have access to an LPC anytime soon in order to get an answer.

unless my Bhutan airways what?:confused:

I thought it was Druk air that had the modified A319's?

Therecare several A319 operated with the same thrust rating as DrukAir. That particular company would be what you refer to as 'Bhutan Airways'?

Ya Druk Air, didnt know the actual name, but they are the national carrier of Buhtan right?

A318 has a bigger rudder. A319-A321 all the same...

The lowest flex in an A320 is 70C (IAE engines) and A319 is 80C (again IAE). So given a equal low weight, you may find as the A319 can flex more, the runway used is slightly more.

Has anyone checked on LPC the Vspeeds and flex of 320 and 319?

Comparing A320 and A319 take off performance
 

A318 has a bigger FIN but the same rudder.

FWIW. 3000m + 15C 1013 dry. AI off opt config

A319 IAE
f77 133 133 136 F2 627mrg
F67 109 119 123 F2 1582 mrg

Forcing flap1
F68 108 122 127 F1 1586 mrg


A319 CFM
F67 119 127 132 1246 mrg F1(opt)

These are Vmcg limited, hence the higher speeds for more powerful engines.

What about A319 Iae vs Cfm engines? It seems Flex is quite similar Vspeeds seem different. On the previous calculation Iae v2 is cfm Vr

The difference is partly due to Vmcg with different engine thrusts. Read the getting to grips on performance book from Airbus.