The 2027 Silverado Engine Chart: ZR2 Keeps Its Diesel, Trail Boss Loses Its Big V8

 8 min read

What the 2027 Silverado ZR2 Engine List Confirms

Order a gas V8 in the next-generation Silverado ZR2 and there is exactly one box to tick: the new 6.6-liter L78 small-block. So the 2027 Silverado ZR2 engine list holds two choices, a diesel and a single V8, according to GM Authority’s trim-by-trim availability table.

Diesel-first structure is nothing new here. Chevrolet made the 3.0-liter Duramax standard on the outgoing ZR2 as well, with the 6.2-liter V8 sitting above it as a paid option. So the news is not the diesel. Rather, it is which V8 sits above it, and which trim lost its biggest option.

Chevrolet revealed the next-generation Silverado 1500 on June 16, 2026, and three lifted trims led the announcement. Since then, the engine picture has firmed up through reporting rather than through GM’s own materials. Our full 2027 Silverado off-road buyer’s guide covers the wider trim walk across all seven models.

2027 Silverado Engine Availability by Trim Level

Chevrolet has published no engine-by-trim chart of its own, so the matrix below comes from GM Authority. Every engine pairs with a 10-speed automatic, so the 2.7-liter moves up from the 8-speed it used before.

What the 2027 Silverado engine matrix shows

Two patterns stand out. First, the 6.6-liter is standard nowhere. It is an option on the ZR2 and the High Country, and absent from every other trim. Second, the ZR2 is the only trim with no four-cylinder available at all. One wrinkle sits inside the Silverado trim, because its fleet-oriented 2FL equipment group runs the TurboMax alone while the 1LT group adds the diesel and the 5.7-liter.

Both gas names are new. The 5.7-liter L76 replaces the 5.3-liter L84, while the 6.6-liter L78 replaces the 6.2-liter L87, and both belong to GM’s Gen 6 Small Block family. Owners following GM’s 6.2L V8 troubles will read the L87’s exit as good news, since recall 25V-274 covers roughly 600,000 trucks and SUVs for connecting rod and crankshaft defects.

Mud-terrain tires change ownership before they change traction. A 35-inch tread packs clay into wheel barrels and body seams. Grit trapped in a wash mitt then drags across fresh paint, which is how a two-month-old truck picks up swirl marks. These four cover the pre-soak and decontamination stage.

	Best Pre-Soak	Top Pick	Best Wash Mitt	Best Add-On
Product	Chemical Guys TORQ Foam Cannon	TOP PICKAdam's Wheel & Tire Cleaner	Chemical Guys Chenille Mitt	Grit Guard Bucket Insert
Rating	★★★★☆ 4.4 823 ratings	★★★★☆ 4.5 5,752 ratings	★★★★★ 4.7 18,064 ratings	★★★★★ 4.7 938 ratings
Size	32 oz bottle	16 oz bottle	Single mitt	Fits 3.5-5 gal
Setup	Pressure washer needed	Ready to use	Two-bucket wash	Drop-in insert
Price	$74.75 as of Aug 19, 4:46 pm	$11.99 as of Aug 19, 4:46 pm	$8.99 as of Aug 19, 4:46 pm	$24.95 as of Aug 19, 4:46 pm
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What the 2027 Trail Boss Gains and Gives Up

The Trail Boss engine story is the one worth watching, because the trim lost its top option. Its 2027 ceiling is the 5.7-liter V8, and Chevrolet has not published output for it. Set against the 420-horsepower 6.2-liter offered in 2026, the new top engine looks like a sideways trade at best.

Hardware around the engine did improve. Trail Boss carries 34-inch mud-terrain tires, a 2-inch factory lift and a dedicated off-road hood. Meanwhile the Custom Trail Boss gets the same lift and tires without the unique bodywork. Chevrolet also made the Z71 package standard on every Silverado 4WD, so off-road suspension, skid plates and hill-descent control now reach trucks below the Trail Boss.

What Trail Boss still lacks is the front locker and the Multimatic DSSV dampers. On off-camber ledges and in deep ruts, a rear locker alone leaves a front wheel spinning, and the gap widens as terrain gets technical. Our explainer on what the ZR2 badge adds walks through the step up in detail, though the short version is simple. Trail Boss is a capable trail truck. ZR2 is a purpose-built one.

Why the Diesel Still Anchors the ZR2

Making a turbo-diesel the default on a halo off-road truck reads oddly next to the Raptor and the RHO. Both of those rivals sell on gas-engine noise. For overlanders, though, the logic holds. The outgoing 3.0-liter produced 305 horsepower and 495 lb-ft, and because torque arrives low, you crawl a ledge without the throttle sensitivity of a big-bore V8.

Towing follows the same pattern. The previous ZR2 towed 8,900 pounds with the diesel against 8,800 with the 6.2-liter, so buyers gave up nothing by skipping the V8. Chevrolet has not published 2027 tow ratings. Still, a torque-heavy six paired with a 10-speed points in the same direction.

The 2027 Silverado ZR2 Engine Numbers Chevy Withheld

Chevrolet released the trim structure while holding back nearly every figure buyers use to compare trucks. As of publication, the company has announced no horsepower or torque for any 2027 powertrain. Payload, tow ratings, fuel economy, ground clearance, approach angles and pricing also remain unpublished.

Circulating figures for the 6.6-liter L78 sit around 475 horsepower, and no outlet sources them to GM. Treat the number accordingly. The safer read is structural. A 6.6-liter Gen 6 Small Block, related to the Corvette’s 6.7-liter, should clear the 420 horsepower of the engine it replaces.

Pricing arrives before the end of the year. For reference, the 2026 ZR2 opens at $71,800 before destination, so under $80,000 would read as restrained for the new truck.

What Chevrolet has confirmed

Confirmed content is generous even without numbers. ZR2 gets 35-inch mud-terrain tires, a 2-inch lift and a power-dome off-road hood. Standard front and rear electronic lockers arrive too, plus GM’s first forged carbon trim. Super Cruise is standard, and the cabin stacks a 16.3-inch center screen, a 12.2-inch cluster and an 11.5-inch passenger display.

What the ZR2 Bison Adds for 2027

The ZR2 Bison returns as the armored version, built with American Expedition Vehicles. It adds front and rear AEV bumpers, rocker protection and 18-inch beadlock-capable wheels. Skid plates cover the front underbody, transfer case, rear differential and fuel tank. All-weather floor liners and an AEV rear badge finish the package.

Two details deserve care. Beadlock-capable means the wheels accept a beadlock ring rather than shipping with one, so deep airing down still risks unseating a bead without a locking ring. Also, the AEV front bumper is cut for clearance, although Chevrolet has published no angles to prove the gain.

Underneath, Multimatic DSSV spool-valve dampers carry over on every ZR2, joined by new jounce dampers at the top of travel. Those spool valves are why a ZR2 stays composed across desert whoops instead of packing down. After a year with a Colorado wearing the same damper design, the difference shows up on washboard first. Our year with a ZR2 covers how the hardware holds up over 12 months.

Stepping from 33-inch to 35-inch tires on the same 2-inch lift raises the truck about an inch overall. Larger mud-terrains bring real tradeoffs in road noise, tread wear and fuel economy, which our breakdown of what 35-inch mud-terrains cost you lays out with numbers.

AEV steel guards the underbody. Nothing guards the paint or the dashboard. Mud-terrain spray etches clear coat, and trail dust bakes into a dash in one summer. These three cover drying, sealing and interior cleanup.

	Top Pick	Best Drying Towel	Best Interior
Product	TOP PICKAdam's Graphene Ceramic Spray	The Rag Company Gauntlet Towel	Chemical Guys Total Interior
Rating	★★★★☆ 4.5 2,211 ratings	★★★★★ 4.7 6,101 ratings	★★★★☆ 4.6 44,392 ratings
Use	Paint sealant	Drying	Interior cleaner
Detail	Spray and wipe off	900 GSM, 2-pack	Vinyl, plastic, leather
Price	$35.69 as of Aug 19, 4:46 pm	$32.95 as of Aug 19, 4:46 pm	$11.97 as of Aug 19, 4:46 pm
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The 6.6-Liter V8 vs Raptor’s EcoBoost and RHO’s Hurricane

A direct engine comparison is impossible right now, because Chevrolet has published no output for the L78. Its rivals have. Ford’s F-150 Raptor runs a 3.5-liter High-Output EcoBoost V6 rated at 450 horsepower and 510 lb-ft. Ram’s 1500 RHO uses the 3.0-liter Hurricane High Output straight-six at 540 horsepower and 521 lb-ft. Toyota’s Tundra TRD Pro pairs an i-FORCE MAX hybrid V6 with 437 horsepower and 583 lb-ft.

GM has made exactly one claim about the new engine, calling it the most powerful naturally aspirated V8 in its class. Read the qualifier closely. Class here means half-ton gas and diesel pickups, while naturally aspirated excludes both the turbocharged Raptor and the turbocharged RHO by definition. So the claim settles nothing against either rival.

Note also what the rival engines sit inside. Raptor and RHO both ride on 35-inch all-terrains with a rear locker only, so no rival outside GM pairs dual electronic lockers with standard 35-inch mud-terrains. On price, Raptor stickers at $81,800 and RHO at $76,885, which brackets where a ZR2 has to land.

Mud-terrains and a front locker point at rock and mud rather than desert running. Neither Raptor nor RHO is trying to win a ledge climb. Likewise, the ZR2 is not chasing a 70-mph whoop section.

Buyers cross-shopping inside GM should look at the GMC Sierra AT4X sibling truck. It runs 35-inch mud-terrains and dual e-lockers too, on the same platform and the same new V8s.

What to Do If You Are Shopping Now

Three moves make sense this fall. First, tell your dealer which trim and engine you want before pricing posts, so you are on the list early. Second, if you want a 2.7-liter truck, plan on waiting, since reporting suggests those builds start later in the first quarter of 2027 while early production skews toward V8 models.

Third, price the outgoing truck honestly. Current-generation Trail Boss and ZR2 stock sits on lots, often with incentives attached. The 6.2-liter recall makes the outgoing gas V8 a harder recommendation, so the decision tilts toward waiting or toward the current diesel.

For ZR2 shoppers, the two-engine menu removes a decision rather than adding one. You take the Duramax diesel or you pay up for the 6.6L V8, and Chevrolet has not yet said what the V8 does. Sharper still is the Trail Boss engine question, because the trim buyers liked in 2026 gave up its headline engine.

Frequently Asked Questions

What engine comes standard in the 2027 Silverado ZR2?

The 3.0-liter Duramax turbo-diesel inline-six is the standard engine, as it was on the outgoing truck. GM Authority’s availability table lists the 6.6-liter L78 V8 as the only alternative. No 2.7-liter or 5.7-liter option appears on the trim.

Can you get the 6.6-liter V8 in a 2027 Trail Boss?

No. Both the Trail Boss and the Custom Trail Boss top out at the 5.7-liter V8 at launch. The 2026 LT Trail Boss offered the 6.2-liter, so this represents a step down in maximum displacement for the trim.

How much horsepower does the 2027 Silverado ZR2 engine make?

Chevrolet has announced output for no 2027 powertrain. Figures circulating online, including roughly 475 horsepower for the 6.6-liter, come from unofficial reporting rather than from GM.

Which 2027 Silverado trims get the 6.6L V8?

Only two. GM Authority’s table lists the 6.6-liter L78 as an option on the ZR2 and the High Country, and as standard equipment on neither. Four trims top out at the 5.7-liter L76, while the Custom is limited to the TurboMax four-cylinder.

What is the RPO code for the 2027 Silverado 5.7L V8?

L76, replacing the 5.3-liter L84. The 6.6-liter carries RPO L78 and replaces the 6.2-liter L87. Meanwhile the TurboMax four-cylinder becomes L4B, and the Duramax stays LZ0 as a carryover.