2027 Silverado 1500 / Sierra 1500 Powertrain Specs: Gen-6 5.7L & 6.6L V8s, TurboMax 350 hp, Duramax Tow Numbers

GM just locked the 2027 Chevrolet Silverado 1500 and GMC Sierra 1500 light-duty powertrain sheet: an Enhanced TurboMax four, the Duramax 3.0L turbo-diesel, and two new Gen-6 Small Block V8s — the L76 5.7L (402 hp / 428 lb-ft) and the L78 6.6L (481 hp / 501 lb-ft). Every engine pairs with a 10-speed automatic. When properly equipped, Silverado’s maximum available tow rating is 13,700 lbs (Sierra 13,500) on the 5.7L — GM’s best-in-class claim. MSRP is still forthcoming; do not expect pricing in this release.

This is gas and diesel light-duty news — not Silverado EV, not RHO, not a spy scoop. The V8s are scheduled to be available at launch later this year. Numbers below come straight from GM’s September 17, 2026 press table.

2027 Silverado / Sierra powertrain specs

*Maximum towing and payload vary by vehicle configuration, trim, and available packages (GM).

What changed vs prior light-duty engines

• Enhanced TurboMax: +40 hp and +25 lb-ft vs the prior TurboMax — now 350 hp / 455 lb-ft. Updates include a new turbocharger, upgraded fuel injection, improved active thermal management, and redesigned pistons. It now pairs with the 10-speed automatic (was 8-speed).
• Duramax 3.0L: Still 305 hp / 495 lb-ft. GM lists DEF-level indicator revisions plus piston, turbo vane, next-gen NOx sensor, sealing, and fuel-injector corrosion-protection updates.
• Gen-6 V8s (L76 / L78): Displacement steps up from the prior 5.3L / 6.2L by increasing piston stroke 6 mm. GM cites higher compression ratio, larger throttle diameters, new tuned intake manifolds, dual direct + port injection (DI+PFI), and a continuously variable oil pump with on-engine oil cooler. The 6.6L is billed as the most powerful naturally aspirated V8 in the segment at 481 hp.
• Fuel tank / range: An optional ~34-gallon tank is available. With Duramax, GM estimates highway range over 900 miles — based on GM-estimated 27 hwy mpg (2WD) plus the ~34-gal tank. That is a GM estimate; real-world range may be lower.

TruckDaily take

Who this is for. Shoppers comparing 2027 half-ton gas and diesel powertrains who need extractable hp/torque/tow/payload numbers before MSRP drops. Tow-first buyers should start with the L76 5.7L row (13,700 / 13,500 max tow*). Payload-first buyers should start with Enhanced TurboMax (2,340 / 2,310*). Long-haul diesel shoppers stay on Duramax for torque and the GM-estimated 900+ mile highway claim with the optional tank.

Who should skip. Skip treating the L78 6.6L as the tow champ — it is the hp leader (481), but GM’s table lists max tow at 9,700 / 9,400*, under the 5.7L and Duramax rows. Skip inventing MSRP or EPA labels — GM says pricing comes in a later update. Skip confusing this with Silverado EV or RHO coverage.

What we’d buy (on paper, pre-MSRP). Tow-max work truck: 5.7L L76 when properly equipped. Everyday gas with strong torque and payload: Enhanced TurboMax. Highway / diesel torque: Duramax 3.0L plus the optional ~34-gal tank if the GM range estimate matters to your route. Peak NA V8 power: 6.6L L78 — accept the lower listed max tow for the 481 hp.

Build plants and launch timing

GM says Gen-6 5.7L and 6.6L V8 production is planned at Flint Engine Operations, with additional capacity at Tonawanda Propulsion and St. Catharines Propulsion. The new V8s are planned to be available with the next-generation Silverado 1500 and Sierra 1500 launch later this year. Chevrolet’s upcoming-vehicles page names the engines and still lists pricing as forthcoming.

FAQ

Sources

• GM press (Public mirror) — Gen-6 Small Block V8 / 2027 light-duty powertrain (distributed Sep 17, 2026 ~08:15 ET)
• Road & Track — 2027 Silverado / Sierra engine details (Sep 17, 2026)
• Chevrolet — 2027 Silverado 1500 upcoming vehicles (engines named; pricing forthcoming)