After some testing I have came to some conclusions:
- Base chance to find items is 2 %. I was testing it on urgent coal and silver contracts - 340 contracts with non-upgraded Decapods and Pacifics gave me 7 drops, 7/340*100 is 2.06 %.
- Challenger's and Liberties starting chance to find items is 8 %. Over 250 rapid contracts (speeded) has dropped 21 item, 20/250*100 is 8 %. Based on visuals on train stats I assume that first upgrade on Challenger adds 6 % more, so it nets to 14 %. Third upgrade adds 8 % more, so final value should be 22 %.
- Based on tests and visuals I assume that whole chance to find items bar equals 24 %.
- Upgraded Mogul's chance is 6 %.
- tests on Challenger (non-upgraded) and Liberty with urgent coal contracts led to 6 drops out of 156 contracts, so 6/156*100 is 3.85 %. This makes me to believe that rapid contracts has 0.5 multiplicator on non-base chance to find items.
If someone could approve this, I would be grateful.