* Based on opinions and should be considered as general guidance only.
- Reliability (4)GMC Sierra models generally have a good reputation for reliability, and the 2021 AT4 is expected to follow suit with robust components and powertrains.
- Maintenance (3)Maintenance costs are typical for a full-size truck, with parts and labor being more expensive than smaller vehicles. Fuel economy, especially with the V8, will be a significant ongoing cost.
- Technology (4)The infotainment system is user-friendly with a responsive touchscreen and good integration for Apple CarPlay/Android Auto. Available safety features are helpful, though not class-leading in every aspect.
- Comfort (4)The cabin is spacious and the seats are generally comfortable, even on longer drives. Road noise is well-managed for a truck, contributing to a pleasant experience.
- Dynamics (4)The AT4's off-road suspension and all-terrain tires provide excellent capability on unpaved roads, absorbing bumps effectively. On pavement, it's competent for a truck, though not car-like in handling.