The GM C1 platform, sometimes referred to as C1XX, is a vehicle architecture designed to underpin midsize and full-size crossovers with internal combustion engines.
Pronounced “Chi”, C1 is the crossover variant of GM’s midsize E2XX architecture. It succeeds GM’s Theta Premium, Theta Epsilon and Lambda platforms.
Features
C1 is highly modular and capable of supporting midsize and full-size crossovers. It has been engineered to be lightweight, highly flexible, and to possess exceptional driving dynamics.
Several key elements of the architecture include:
- Front-engined, transversely-mounted powertrain layout
- A four wheel independent suspension system
- Front- and all-wheel-drive applications
- Regular and extended wheelbase configurations
- Support for two- and three-row seating
- Ample trunk/cargo space with the third-row seats up in long-wheelbase models, one of the key differentiators of these models
The GM C1 platform was developed with support for two wheelbases – a regular (short) wheelbase, and a long wheelbase. Regular wheelbase applications of the C1 platform (V1 in the table below) deliver crossover utility vehicles sized as midsize or midsize-plus models, with either two or three rows of seating, depending on configuration. Long wheelbase applications of the C1 platform (V2 below) deliver crossover utility vehicles with full-size proportions and with three rows of seating. Once these two variants were introduced, GM then rolled out two other variants of the short-wheelbase version. Both of these built on the regular (short) wheelbase version by extending the track width (V3 below), which resulted in a slight increase in wheelbase, or extending the track width while also extending the length of the rear overhang in order to accommodate a third row (V4 below), which also caused a slight increase in the wheelbase length.
| Vehicle | Model Code | Platform Variant | Production Facility 1 | Production Facility 2 | Model Years |
|---|---|---|---|---|---|
| Cadillac XT5 | C1UL | V1 – regular wheelbase, narrow track | Spring Hill, TN, USA | Jinqiao Cadillac, Shanghai, China | 2017-present |
| GMC Acadia | C1UG | V1 – regular wheelbase, narrow track | Spring Hill, TN, USA | - | 2017-2023 |
| Chevrolet Traverse | C1YC | V2 – long wheelbase, wide track | Delta Township, Michigan, USA | - | 2018-2024 (Traverse Limited) |
| Buick Enclave | C1YB | V2 – long wheelbase, wide track | Delta Township, Michigan, USA | - | 2018-2024 |
| Chevrolet Blazer 2-row | C1UC | V3 – regular wheelbase, wide track, short rear end | Ramos Arizpe, Mexico | - | 2019-2024 |
| Cadillac XT6 | C1TL | V4 – regular wheelbase, wide track, long rear end | Spring Hill, TN, USA | Jinqiao Cadillac, Shanghai, China | 2020-2025 |
| Buick Enclave (China only) | C1UB | V4 – regular wheelbase, wide track, long rear end | - | Jinqiao Cadillac, Shanghai, China | 2021-present |
| Chevrolet Blazer 3-row (China only) | C1UC-S | V4 – regular wheelbase, wide track, long rear end | - | Jinqiao Cadillac, Shanghai, China | 2021-present |
| Chevrolet Traverse | C1YC-2? | V2 – long wheelbase, wide track gen 2 | Delta Township, Michigan, USA | - | 2024-present |
| GMC Acadia | C1UG-2? | V2 – long wheelbase, wide track gen 2 | Delta Township, Michigan, USA | - | 2024-present |
| Buick Enclave | C1YB-2? | V2 – long wheelbase, wide track gen 2 | Delta Township, Michigan, USA | - | 2025-present |
| Cadillac XT5 (China only) | C1UL-2? | V1 – regular wheelbase, narrow track gen 2 | Jinqiao Cadillac, Shanghai, China | - | 2024-present |
Specifications
| Type: | Unibody welded steel body |
| Size: | Midsize or Full-Size |
| Supported vehicle type: | Crossover SUV (CUV) |
| Layout: | Transverse front engine |
| Drivetrain: | FWD or AWD |
| Predecessor: | Theta-Epsilon (regular wheelbase C1 models) and Lambda (long wheelbase C1 models) |
| Related: | E2XX |
| Successor: | C1-2 |
Engines
C1 supports various GM four-cylinder Ecotec and six-cylinder GM engines.
C1 Applications (First Gen)
The first-generation GM C1 platform underpinned a total of eight vehicles globally.
Regular Wheelbase
- First-gen Cadillac XT5
- Second-gen GMC Acadia
- Fifth-gen Chevrolet Blazer
- First-gen Cadillac XT6
- Chinese market Chevrolet Blazer three-row
- Chinese-market Buick Enclave
Long Wheelbase
- Second-gen Chevrolet Traverse
- Second-gen Buick Enclave
First-gen Cadillac XT5
Second-gen GMC Acadia
Second-gen Chevrolet Traverse
Second-gen Buick Enclave
Fifth-gen Chevrolet Blazer
First-gen Cadillac XT6
Three-row Chevrolet Blazer for Chinese market
Buick Enclave for Chinese market
C1-2 Applications (Second-Gen)
A second iteration of C1, known as C1-2, made its debut in conjunction with the third-generation Chevy Traverse, before making its way across several other models. the second generation is noteworthy for adopting the GM Global B electric architecture. The second generation of the C1 platform underpins fewer models than C1 due to GM’s aggressive transition to battery electric vehicles (BEVs).
Regular Wheelbase
- Second-gen Cadillac XT5 (China only)
Long Wheelbase
- Third-gen Chevrolet Traverse
- Third-gen GMC Acadia
- Third-gen Buick Enclave
Third-gen Chevrolet Traverse
Third-gen GMC Acadia
Third-gen Buick Enclave
Second-gen Cadillac XT5
