For each weapon, what are the improvements when you 'level up' or upgrade them?

Question

For each weapon, what are the improvements when you 'level up' or upgrade them?

Answer 1

Definitely more damage and more ammo. But it depends on the weapon.

For example:

• Shotgun has 4 ammo for Level 0 versus 6 ammo for Level 9.
• Gatling has 80 ammo Level 0 versus 128 ammo for Level 9.

I can't tell the exact amount of damage, as there are no references to the car hit points or weapon damage. There's not much difference between levels, but it is significant between first and last levels.

It would be great to have more complete stats in this topic.