LZ0 Duramax Specs: GM Engineering Reference

Direct answer: the core LZ0 specification sheet

GM's current LZ0 reference specifies a longitudinal 2,999-cc/183-cu-in inline-six turbo-diesel with an 84-mm bore, 90-mm stroke and 15.2:1 compression ratio. It uses dual overhead camshafts, four valves per cylinder, mechanical roller lifters and firing order 1-5-3-6-2-4.

The same source lists 305 hp/227 kW at 3,750 rpm, 495 lb-ft/671 Nm at 2,750 rpm and a 5,000-rpm maximum engine speed. GM says 94 percent of maximum torque is available by 1,500 rpm. Apply these fields only after confirming LZ0 identity and the matching application.

Confirm LZ0 before copying any value

The 3.0L Duramax name spans LM2 and LZ0 generations. GM calls LZ0 the second generation after LM2, but displacement, exterior appearance or a listing title cannot certify the installed RPO. Record the model year, vehicle line, market, engine code and original documentation before assigning the specification row.

Transition-year, replacement-engine and modified vehicles need additional build and service evidence. If authoritative records conflict, leave the candidate field unresolved rather than choosing the newer or more attractive number.

Displacement and cylinder arrangement

GM publishes 2,999 cubic centimetres and 183 cubic inches for LZ0. The 3.0L marketing name is a rounded displacement class, while the source's detailed value is the appropriate engineering reference. The six cylinders are arranged inline and the engine is installed longitudinally in the cited architecture.

Those fields help distinguish design layout; they do not identify a private engine, establish condition or prove parts fitment. Use current catalogue and VIN-specific service information for ordering or repair.

Bore, stroke and compression ratio

The cited bore is 84 mm and stroke is 90 mm. GM lists a 15.2:1 compression ratio. These are nominal design specifications, not measurements of cylinder wear, piston protrusion, cranking pressure or combustion health in a used engine.

Do not transfer them to LM2 without equivalent LM2 evidence or treat a matching measurement as proof of LZ0 identity. Repair tolerances, measurement methods and reuse limits belong to current service information.

Valvetrain and firing order

GM specifies dual overhead camshafts, four valves per cylinder and mechanical roller lifters. The published firing order is 1-5-3-6-2-4. Together these fields describe architecture; they are not a timing, lash or disassembly procedure.

A firing-order reference cannot diagnose a misfire by itself. Identify the affected cylinder, codes, operating conditions and test evidence, then use the current diagnostic procedure for the exact vehicle.

Read power with its engine speed and footnote

The LZ0 reference states 305 hp, or 227 kW, at 3,750 rpm. GM footnotes the output as tested in Chevrolet Silverado. Preserve the value, engine speed and test application together; omitting the footnote turns a bounded engineering row into an unsupported universal claim.

Factory engine horsepower is not wheel horsepower. Drivetrain losses, test method, calibration, environment and vehicle condition affect a chassis-dynamometer result. The dedicated horsepower page retains that focused intent.

Torque has three distinct source fields

GM publishes 495 lb-ft, or 671 Nm, at 2,750 rpm and separately states that 94 percent of maximum torque is available by 1,500 rpm. That latter statement means approximately 465 lb-ft when applying the published percentage, but the calculated value is editorial arithmetic rather than a separately quoted GM rating.

Keep peak magnitude, peak speed and early-availability statement distinct. None supplies a full torque curve, wheel torque, axle torque or towing limit. The dedicated LZ0 torque page remains a separate planned intent.

Maximum engine speed is not a shift command

The technical table lists 5,000 rpm as maximum engine speed. That field does not say the engine produces peak power there, recommend routine operation at that speed or define transmission shift strategy. Peak power is separately stated at 3,750 rpm.

Follow the vehicle's controls, warnings and exact owner documentation. Calibration, protection logic, transmission behaviour and service limits cannot be reconstructed from one maximum-speed row.

What Chevrolet says changed from LM2

Chevrolet's launch record compares the new LZ0 with the cited 2022 LM2: 305 versus 277 hp and 495 versus 460 lb-ft. Chevrolet labels the differences as 10 percent more horsepower and 7.6 percent more torque. Those are launch comparisons, not a complete chronology for every LM2 or LZ0 application.

The release attributes the change to new steel pistons with revised combustion bowls, a retuned turbo compressor, new fuel injectors and temperature-control improvements. A named revision does not establish its independent contribution or a reliability outcome.

Materials must stay component-specific

GM lists a cast-aluminum block and cylinder head, composite intake manifold, nodular-iron exhaust manifold and main-bearing caps, forged-steel crankshaft and connecting rods, and an assembled-steel camshaft. Do not compress that mixture into an all-aluminum or all-steel description.

Material names describe the cited production design, not crack status, heat exposure, wear, repairability or the composition of a replacement component. Candidate condition still requires inspection and appropriate tests.

The live GM materials-table anomaly

During the 13 September 2026 review, GM's live materials table labelled its final two rows Connecting Rods and gave Forged Steel for both. This guide does not silently rename the second row to Pistons or claim that the table itself labels piston material.

Steel-piston evidence instead comes from GM's separate LZ0-refinements prose and Chevrolet's launch release. Preserving the source anomaly keeps the evidence auditable and avoids inventing a corrected table that GM did not publish.

Direct injection and injector revision

The engineering table lists direct injection. GM's refinements text adds that new injectors were designed to control higher fuel pressure with an optimized spray pattern. It does not publish the pressure number in the reviewed passage, so this page leaves that numeric cell unresolved.

Do not infer rail pressure, injector correction values, service life or diagnostic thresholds from the design description. Those require exact service data and candidate measurements.

Turbocharger language remains bounded

GM says the revised turbocharger assists with increased torque, while Chevrolet describes a retuned turbo compressor. Those statements support a named LZ0 revision, not a compressor map, boost target, part number or quantified share of the output gain.

Factory output also does not approve aftermarket calibration or hardware. Modified vehicles require installed-part, tune, emissions-compliance and measured-condition evidence.

Fuel rows are compatibility fields, not economy results

GM lists ultra-low-sulfur diesel and B20 biodiesel. The exact vehicle supplement governs quality, biodiesel procedures, cold-weather handling and warnings. A short technical row should not replace the owner documentation for the model year and market.

Fuel compatibility does not publish L/100 km, range or cost. Those depend on the complete vehicle, configuration, route, load, temperature and measurement method.

The emissions system is an integrated chain

GM identifies high-pressure uncooled EGR, low-pressure cooled EGR, a close-coupled diesel oxidation catalyst, selective catalytic reduction on the particulate filter, downstream SCR and an ammonia-slip catalyst. Preserve those components as an application-specific system rather than reducing it to DPF and DEF.

The component list does not establish present health, fault prevalence or remaining life. Warning messages, codes, tampering and repairs require exact-vehicle diagnosis. This guide does not approve emissions deletion or defeat.

Oil-pump-belt wording is a service boundary

GM says the LZ0 oil-pump belt was validated to a 200,000-mile service interval, described as a 33-percent increase from 150,000 miles. Preserve the exact component and design statement; it is not an engine-life guarantee or proof of belt condition.

The reviewed 2024 maintenance schedule independently supplies the actionable 200,000-mile/15-year replacement row. Keep engineering validation, scheduled service and completed candidate work as three separate evidence fields.

Launch transmission context is not universal

Chevrolet's 2023 launch release says the LZ0 would be paired exclusively with a 10-speed automatic for retail customers in the named select Silverado trims. That establishes launch context, not the transmission code, ratios or availability for every later Chevrolet, GMC or SUV.

Verify the complete build before comparing gearing or service needs. Engine torque cannot establish axle torque without gear and axle ratios, and a 10-speed label cannot establish condition.

Fluids and capacities remain on separate pages

An engine specification sheet does not safely collapse oil quantity, oil approval, coolant capacity and maintenance timing. The reviewed LZ0 sources distinguish these fields, and application-specific cooling rows demonstrate why a single engine-family capacity is unsafe.

Use the dedicated oil-capacity and oil-type guides for 6.6 L/7.0 U.S. qt with filter and dexosD SAE 0W-20. Use the maintenance guide for timing. A correct architecture row cannot substitute for any of them.

Engine output does not determine truck capacity

The 305-hp and 495-lb-ft engine ratings do not create a tow or payload number. Complete-vehicle limits depend on model, cab, bed, drive, axle, GVWR, GCWR, curb and option weight, tires, hitch and other equipment.

Use the exact vehicle labels and configuration-specific manufacturer guide. Do not transfer a family maximum to a Canadian VIN or use engine torque to bypass axle, tire, payload and hitch limits.

Specifications cannot rank reliability

Architecture, materials and output describe a design; they do not publish a failure rate, best year, expected lifespan or candidate condition. Steel pistons and a revised turbo do not prove that every LZ0 outlasts every LM2, and higher output does not prove the opposite.

Keep recalls, service bulletins, symptoms, maintenance, modifications and inspection findings in separate lanes. The dedicated problems and reliability pages retain those intents.

Create a candidate-specific specification record

Record the vehicle line, model year, engine RPO, market, source title, source date and every copied value with units and application notes. Keep manufacturer architecture, owner-manual service data, vehicle labels, recall results and measured condition in separate sections.

For a replaced or modified engine, retain the replacement identity, invoice, calibration and installed-component records. Factory LZ0 values do not certify modified output or current compliance.

Keep the LZ0 page distinct from the family comparison

The established 3.0L Duramax specifications guide compares LM2 and LZ0 and keeps unsupported cross-generation cells blank. This page owns the narrower LZ0 query, expands the LZ0 engineering table and documents the live materials-label anomaly. Neither canonical replaces the other.

Horsepower, torque, fluids, maintenance, problems, reliability, best-year and years-to-avoid remain separate intents. A specification index may link to them but cannot absorb their evidence or conclusions.

LZ0 specifications checklist

Use this checklist before copying a number into a comparison, listing audit or service file.

• Verify the model year, vehicle line, market and LZ0 engine code.
• Record 2,999 cc and the inline-six longitudinal layout with source date.
• Keep 84 × 90 mm and 15.2:1 as nominal design fields.
• Attach 305 hp to 3,750 rpm and the Chevrolet Silverado test footnote.
• Attach 495 lb-ft to 2,750 rpm; label 94 percent by 1,500 rpm separately.
• Do not treat 5,000 rpm as a recommended shift point.
• Preserve each material row and the live table's duplicated label.
• Use separate sources for steel-piston and launch-revision claims.
• Keep fuel, emissions, fluid, maintenance and capacity fields distinct.
• Verify towing and payload from the complete vehicle.
• Do not infer reliability, Canadian VIN status or candidate condition.
• Do not invent inventory, sellers, dealer counts, prices or offers.

Frequently asked questions

What are the main LZ0 specs? GM publishes 2,999 cc, 84 × 90 mm bore and stroke, 15.2:1 compression, DOHC four-valve architecture, 305 hp at 3,750 rpm and 495 lb-ft at 2,750 rpm. Are those wheel figures? No; they are factory engine-reference values tested in Chevrolet Silverado.

Is LZ0 the same as LM2? No. GM identifies LZ0 as the second generation, and Chevrolet's launch comparison lists the 2022 LM2 at 277 hp and 460 lb-ft. Does 495 lb-ft establish towing capacity or reliability? No. Verify the complete truck and assess condition through separate evidence.

Editorial conclusion

The defensible LZ0 specification reference is the GM-published engineering row with its labels intact: a 2,999-cc longitudinal inline-six, 84 × 90 mm dimensions, 15.2:1 compression, DOHC four-valve architecture, 305 hp at 3,750 rpm and 495 lb-ft at 2,750 rpm, footnoted as tested in Chevrolet Silverado.

Preserve the source's application limits and visible anomaly rather than completing unsupported fields. Keep engine design separate from wheel output, truck ratings, fluids, maintenance, diagnosis, reliability, Canadian VIN certification and commercial availability.