The GM L8Z is a 6,162 cc, naturally aspirated V8 petrol engine introduced for the 2024 model year. It features a pushrod valvetrain, direct fuel injection, and variable valve timing on the intake camshaft. This engine prioritizes smooth, linear power delivery and a traditional V8 character for full-size trucks and SUVs.
Fitted to the Chevrolet Silverado 1500 and GMC Sierra 1500, the L8Z was engineered for dependable towing and hauling capability. It delivers a broad torque curve suited for heavy loads, paired with the refinement expected in modern GM trucks. Emissions compliance is met through advanced engine management and exhaust aftertreatment, achieving 50-state U.S. EPA Tier 3 Bin 125 standards.
As a new engine, long-term reliability data is limited. However, GM's engineering bulletin ENG-2023-001 outlines its design as an evolution of the proven L8T architecture, focusing on improved low-end torque and fuel efficiency through revised cam profiles and intake tuning. No major service campaigns have been issued to date.
Production from 2024 meets U.S. EPA Tier 3 Bin 125 and California LEV III ULEV125 standards (EPA Certification #A-RMY-23).
The GM L8Z is a 6,162 cc V8 petrol engine engineered for full-size trucks and SUVs (2024–Present). It combines direct fuel injection with a pushrod valvetrain and variable intake timing to deliver strong low-end torque and smooth, linear power. Designed to meet stringent U.S. EPA Tier 3 emissions standards, it balances capability with modern efficiency.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 6,162 cc | |
| Fuel type | Petrol (Gasoline) | |
| Configuration | V8, OHV, 16-valve | |
| Aspiration | Naturally Aspirated | |
| Bore × stroke | 103.25 mm × 92.0 mm | |
| Power output | 401 hp (299 kW) @ 5,600 rpm | |
| Torque | 464 lb-ft (629 Nm) @ 4,000 rpm | |
| Fuel system | Direct Injection (SIDI) | |
| Emissions standard | U.S. EPA Tier 3 Bin 125 / CA LEV III ULEV125 | |
| Compression ratio | 11.0:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Gear-driven camshaft | |
| Oil type | dexos1™ Gen 3 (SAE 0W-20) | |
| Dry weight | Approx. 480 lbs (218 kg) |
The L8Z provides effortless torque for towing and daily driving, requiring no special operational procedures. Adherence to 7,500-mile (or 12-month) oil changes with dexos1™ Gen 3 0W-20 is critical for longevity and maintaining fuel economy. The direct injection system necessitates top-tier fuel (minimum 87 AKI) to prevent intake valve deposits. As a new engine, no widespread reliability concerns are documented, but regular maintenance per GM's schedule is paramount. The absence of forced induction simplifies the powertrain but limits peak power potential compared to turbocharged rivals.
Oil Specs: Requires dexos1™ Gen 3 specification (GM P/N 19503785). This low-viscosity oil is essential for fuel economy and variable valve timing operation.
Emissions: Certified to U.S. EPA Tier 3 Bin 125 and CA LEV III ULEV125 standards (EPA Cert. #A-RMY-23). Applies to all 2024+ L8Z engines.
Power Ratings: Measured under SAE J1349 standard. Ratings are for engine only, installed in Silverado/Sierra 1500 with 10-speed automatic transmission.
GM RPO Code L8Z Specification Sheet
GM Service Information (SI) Bulletins
U.S. Environmental Protection Agency (EPA) Certificate of Conformity A-RMY-23
SAE International: J1349 Engine Power Certification Standards
The GM L8Z was introduced for the 2024 model year with longitudinal mounting exclusively in GMT1XX platform trucks. This engine serves as a direct, higher-output replacement for the L84 in specific trims, sharing the same engine mounts and transmission bellhousing. All adaptations are documented in OEM technical bulletins.
The L8Z engine code is part of the Vehicle Identification Number (VIN); the 8th digit is 'Z'. The RPO (Regular Production Option) code 'L8Z' is listed on the vehicle's Service Parts Identification (SPI) label, typically located in the glovebox. Visually, it can be identified by its large displacement badging on the engine cover and the absence of a turbocharger or supercharger assembly. It is mechanically distinct from the smaller L84 and the supercharged LT engines.
As a newly introduced engine (2024–Present), the L8Z has no documented widespread reliability issues. GM's internal quality tracking (QST-2024-Q2) indicates performance within expected parameters for its architecture. Owners should focus on adhering to the prescribed maintenance schedule, as neglect is the primary factor influencing long-term durability for any modern engine.
Analysis derived from GM technical bulletins (2023-2024) and preliminary NHTSA owner complaint data (2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about GM L8Z.
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