Duramax Diesel Timeline

Horsepower & Torque Output by Year

Model Year	Horsepower	Torque	Notes
2001	LB7: 235 hp @ 2,700 rpm	LB7: 500 lb-ft @ 1,600 rpm	Duramax LB7
2002	235 hp @ 2,700 rpm	500 lb-ft @ 1,600 rpm
2003	235 hp @ 2,700 rpm	500 lb-ft @ 1,600 rpm
2004	LB7: 300 hp @ 3,100 rpm LLY: 310 hp @ 3,000 rpm	LB7: 520 lb-ft @ 1,800 rpm LLY: 520 lb-ft @ 1,600 rpm	The LLY was introduced in 2004 and replaced the LB7 completely mid-year.
2005	310 hp @ 3,000 rpm	520 lb-ft @ 1,600 rpm
2006	LLY: 310 hp @ 3,000 rpm LBZ: 360 hp @ 3,200 rpm	LLY: 605 lb-ft @ 1,600 rpm LBZ: 650 lb-ft @ 1,600 rpm	The LBZ was introduced in 2006 and eventually replaced the LLY by 2007. The 2006 LLY featured many changes to boost torque.
2007	LBZ: 360 hp @ 3,200 rpm LMM: 365 hp @ 3,100 rpm	LBZ: 650 lb-ft @ 1,600 rpm LMM: 660 lb-ft @ 1,800 rpm	The LMM was introduced mid-year 2007 and replaced the LBZ.
2008	365 hp @ 3,100 rpm	660 lb-ft @ 1,800 rpm
2009	365 hp @ 3,100 rpm	660 lb-ft @ 1,800 rpm
2010	365 hp @ 3,100 rpm	660 lb-ft @ 1,800 rpm
2011	LML: 397 hp @ 3,000 rpm	LML: 765 lb-ft @ 1,600 rpm	Duramax LML replaces LMM.