54 problems have been reported for the 2021 GMC Terrain. The following chart shows the 15 most common problems for 2021 GMC Terrain. The number one most common problem is related to the vehicle's engine and engine cooling with 11 problems. The second most common problem is related to the vehicle's service brakes, hydraulic (9 problems).
In our research we use the PPMY index to compare the reliability of vehicles. The PPMY index of a certain model is defined as the problems reported per thousand vehicles per Year. The total sales of the 2021 GMC Terrain in the United States are 52,826 units [1]. If the total number of problems reported by GMC Terrain owners in the last 5 years is 54, and the age of the vehicle is 5, the PPMY index can then be calculated as
PPMY Index = 54 / 52,826 / 5 * 1000 = 0.20.
For more information, refer to this page: A study of reliability comparison across GMC Terrain model year vehicles.
The following chart shows the number of problems reported during each of the service years since the debut of the 2021 GMC Terrain in 2021.
| Service Year | Number of Problems |
|---|---|
| 2026 | |
| 2025 | |
| 2024 | |
| 2023 | |
| 2022 | |
| 2021 |
When making the decision between buying a new or used GMC Terrain, the following table can be used to compare the 2021 GMC Terrain with the GMC Terrain from other model years. Note that the number of problems reported for the 2021 Terrain is 54 while the average number of problems reported for the 18 model years of the GMC Terrain is 246.
| Model Year | Number of Problems |
|---|---|
| 2026 Terrain | |
| 2025 Terrain | |
| 2024 Terrain | |
| 2023 Terrain | |
| 2022 Terrain | |
| 2021 Terrain | |
| 2020 Terrain | |
| 2019 Terrain | |
| 2018 Terrain | |
| 2017 Terrain | |
| 2016 Terrain | |
| 2015 Terrain | |
| 2014 Terrain | |
| 2013 Terrain | |
| 2012 Terrain | |
| 2011 Terrain | |
| 2010 Terrain | |
| 2009 Terrain |