Rumble is trash and could use some buffs...
As the title says...
is currently sitting at a 45%-47% win rate:
http://na.op.gg/champion/rumble/statistics/top
http://champion.gg/champion/Rumble/Top?league=
Buffs:
Q: Flamespitter
Danger zone: Damage increased from 50% to 100%; deals double damage (200%) against monsters
E: Electro Harpoon
New Effect Monsters now heal Rumble 8% all ranks of his maximum health per 1% of his missing health
Some of the buffs will also help
in the Jungle.