The GM L8 is a 3,498 cc, naturally aspirated V6 petrol engine produced from 2020 onwards. It features dual overhead camshafts (DOHC), direct fuel injection, and variable valve timing (VVT) to deliver a balance of power and refinement. Peak output is rated at 237 kW (320 PS) and 383 Nm of torque, providing strong mid — range pull for confident overtaking.
Fitted primarily to the Chevrolet Blazer and Cadillac XT4, the L8 was engineered for responsive, everyday performance in m…
Production years 2020–Present meet Euro 6d and U.S. Tier 3 Bin 30 standards (EPA Certificate of Conformity #A-20-001).
The GM L8 is a 3,498 cc V6 naturally aspirated petrol engine engineered for mid-size SUVs (2020-Present). It combines direct injection with variable valve timing to deliver smooth, responsive power and quiet operation. Designed to meet Euro 6d and U.S. Tier 3 Bin 30 standards, it balances performance with stringent emissions control.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,498 cc | |
Fuel type | Petrol | |
Configuration | V6, DOHC, 24-valve | |
Aspiration | Naturally Aspirated | |
Bore × stroke | 95.0 mm × 82.0 mm | |
Power output | 237 kW (320 PS) @ 6,700 rpm | |
Torque | 383 Nm @ 5,000 rpm | |
Fuel system | Direct Injection (SIDI) | |
Emissions standard | Euro 6d / U.S. Tier 3 Bin 30 | |
Compression ratio | 11.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | None | |
Timing system | Chain-driven | |
Oil type | dexos1™ Gen 3 (SAE 5W-30) | |
Dry weight | 168 kg |
The GM L8 was used across GM's Theta platform SUVs with transverse mounting and no external licensing. This engine received platform-specific adaptations-unique engine mounts and accessory drive layouts for the Blazer versus the XT4-creating minor service part differences. All adaptations are documented in OEM technical bulletins.
The L8's primary documented service focus is potential oil consumption on early builds, with elevated incidence under sustained high-RPM driving. GM internal data from 2021 indicated a subset of pre-mid-2021 engines required piston ring updates, while NHTSA data shows no significant safety recalls. High-load driving cycles make adherence to the revised service procedure critical.
Analysis derived from GM technical bulletins (2020-2023) and NHTSA recall data (2020-2024). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The GM L8 is generally robust, with its chain-driven timing and lack of forced induction reducing complexity. The primary concern is oil consumption on pre-mid-2021 builds, which is addressed by a factory service bulletin. With regular maintenance using dexos1™ oil and attention to intake cleaning, it should provide dependable long-term service.
The most common documented issues are excessive oil consumption (early builds), intake valve carbon buildup, VVT actuator rattle on cold starts, and coolant leaks from the thermostat housing. These are addressed in GM service bulletins and are generally manageable with proper maintenance.
The L8 engine is found in the Chevrolet Blazer (RS and Premier trims) and the Cadillac XT4 (Sport and Premium Luxury trims) from the 2020 model year onwards. It is not used in any non-GM vehicles.
Yes, the L8 can be tuned. An ECU remap can yield modest gains of 10-15 kW by optimizing ignition timing and fuel maps. However, as a naturally aspirated engine, significant power increases require internal modifications like camshafts or increased displacement, which are costly and complex.
Fuel economy is competitive for its class. In a Chevrolet Blazer AWD, expect around 11.8 L/100km (city) and 8.4 L/100km (highway), or approximately 24 mpg (US) combined. Real-world figures vary based on driving style, vehicle weight, and conditions.
Yes. The GM L8 is an interference engine. If the timing chain were to fail (an extremely rare event), the pistons would collide with the open valves, resulting in catastrophic internal engine damage requiring a full rebuild or replacement.
GM mandates the use of dexos1™ Gen 3 full synthetic oil, typically in 5W-30 viscosity. Using the correct specification is non-negotiable for warranty compliance and to ensure the longevity of the variable valve timing system and turbocharger (if applicable to other engines).
Comprehensive technical documentation and regulatory references
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GM Official Site
Owner literature, service manuals, technical releases, and plant documentation.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
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