GMC Sierra 2500HD best and worst years

Each year is compared with the typical (middle) complaint count of the heavy-duty trucks we cover from the same model year, using owner complaints filed with NHTSA. Comparing within a year is fairer than one overall ranking, because older trucks have had more time to collect complaints.

Fewest complaints for their age

201835 complaints vs. 127 typical
201932 complaints vs. 105 typical
201798 complaints vs. 245 typical
202243 complaints vs. 103 typical
201665 complaints vs. 131 typical

Most complaints for their age

2011106 complaints vs. 105 typical
201059 complaints vs. 62 typical
2014131 complaints vs. 149 typical
200783 complaints vs. 98 typical
201385 complaints vs. 102 typical

Every year

Year	Complaints	Typical that year	Compared
2007	83	98	About average
2009	68	82	About average
2010	59	62	About average
2011	106	105	About average
2012	60	106	Below average
2013	85	102	About average
2014	131	149	About average
2015	147	178	About average
2016	65	131	Below average
2017	98	245	Below average
2018	35	127	Below average
2019	32	105	Below average
2020	76	112	Below average
2021	51	74	Below average
2022	43	103	Below average

Years not listed are too new to compare fairly, have too few trucks to compare against, or NHTSA lumps them in with other trucks.

What each generation is known for

2007–2010
6.6L Duramax LMM diesel and 6.0L V8 gas
Airbag recalls top the complaints; idler and pitman arm wear and cracked dashes are common; the Duramax LMM is well regarded.
2011–2014
6.6L Duramax LML diesel and 6.0L V8 gas
The Duramax LML's high-pressure fuel pump is the costliest risk; DEF and NOx sensor repairs and airbag recalls are common.
2015–2019
6.6L Duramax diesel (LML 2015–2016, L5P 2017–2019) and 6.0L V8 gas
2015–2016 diesels carry the fuel pump risk; the 2017+ L5P has far fewer fuel pump complaints; trailer brake warnings are common.
2020–2026
6.6L Duramax L5P diesel and 6.6L V8 gas
The 10-speed transmission is the most reported problem, with a valve body recall on 2020–2022 diesels; trailer brake warnings are common.

Read this before deciding. Complaint counts aren't reliability scores. Best-selling trucks collect more complaints simply because more are on the road, and one widely reported problem (or a recall) can drive a year's numbers. The condition and history of the specific truck you're looking at matter more than its year. Always get a pre-purchase inspection and bring our inspection checklist.