Upgrading

 is a mechanic in Crossout that allows players to consume multiple items to produce a single stronger or rarer item. There are 3 different item classes that can be upgraded: parts, decor and paint. To access this mechanic the player needs to have a reputation of 9 or above with the Engineers faction.

Upgrading parts
By upgrading parts you can improve their power, reliability and handling in combat. Upgrading is done by using 3 parts of rare rarity or higher to produce a single upgraded item with a random bonus to the part stats, such as increased durability, reduced weight, or improved damage. The power score of the upgraded part does not increase however despite an improvement in stats. After selecting the parts to upgrade, the game will show you a list of potential modifiers and allow you to cancel the upgrade. Once a part is upgraded, it cannot be traded, or used for crafting, however it can be used again in upgrading process, in which case the new random upgrades will replace the existing ones.

Recycling decor / Mixing paint
By recycling decor / mixing paint you can get a random rarer decor / paint out of 10 parts of lower rarity. This also requires to spend some Coins, Scrap Metal and Copper. After selecting the 10 items, the game will show you a list of possible resulting items and allow you to cancel the recycling.