The The Scorchers Add-on for RAGE has 10 achievements worth 250 gamerscore.
Finish the Campaign on Ultra Nightmare difficulty
Complete Hagar Caves in The Scorchers job path
Complete Refinery in The Scorchers job path
Complete Bash Canyon in The Scorchers job path
Complete Scorcher Base in the The Scorchers job path
Bet and win on Green in the Roly-Poly minigame
Win with a Four of a Kind in the Video Poker minigame
Kill 2 enemies with one Railgun Slug shot through a wall
Pin an enemy to a surface with a Rebar ammo shot
Complete Wellspring Tunnels in The Scorchers job path