Quick Facts:
- Topic: 2027 Silverado MPG ratings for the new V8s and the diesel.
- 5.7L V8: 15/19/17 mpg in 2WD and 15/18/16 mpg in 4WD.
- 6.6L V8: 14/18/15 mpg in High Country and 13/15/14 mpg in ZR2.
- 3.0L Duramax: 22/27/24 mpg in 2WD and 21/23/22 mpg in 4WD.
- Change from 2026: up to 3 mpg lower, with a few ratings unchanged.
- 2.7L TurboMax: no 2027 rating listed yet.
- Source status: GM supplied the ratings, and fueleconomy.gov now lists the same numbers for the V8s and the diesel.
6 min read
In This Article
Overview
The 2027 Silverado MPG numbers are out. Compared with the engines they replace, the new V8s rate one to two mpg lower combined. The ratings GM supplied cover the 5.7L V8, the 6.6L V8 and the 3.0L Duramax diesel. GM Authority first reported them on Nov. 3. For example, the 6.6L ZR2 posts 13 city, 15 highway and 14 combined. Its highway number is two mpg below the 2026 ZR2.
Chevrolet lists 481 hp and 501 lb-ft for the 6.6L and 402 hp and 428 lb-ft for the 5.7L. In addition, the Duramax makes 305 hp and 495 lb-ft. Also, fueleconomy.gov now lists these ratings, so the numbers match the federal listing. However, Chevrolet’s trim-compare page still shows TBD for the TurboMax trim, which has no rating yet.
This guide turns the ratings into gallons, range and towing choices. Tire choice also shifts the results, because the mud-terrain rows run lower than the rest.
Stickers only tell you what the EPA measured, so you also need your own numbers. For example, the ScanGauge 3 plugs into the OBD-II port under the dash of a 1996 or newer light truck and logs instant, average and tank mpg. As a result, you get a baseline to compare against these ratings before you buy.
ScanGauge 3 Touch Screen OBD2 Scanner, Digital Gauges & Trip Computer SG3 | Digital Gauges, WiFi Updates, SG3
A dash-mounted OBD-II trip computer which logs live and average fuel economy on 1996 and newer light trucks.
- Instant, average and tank mpg readouts
- Trip fuel cost and distance-to-empty tracking
- X-Gauge adds extra gauges such as transmission temperature
- Costs more than a phone-based OBD-II dongle
2027 Silverado MPG at a Glance
The table shows city, highway and combined mpg. Its 2026 column comes from the same GM Authority table. For three 2026 setups, fueleconomy.gov lists a second entry without Sport Mode. It rates one mpg lower in a column or more, so check your truck’s sticker before you compare.
| Engine and Setup | 2027 Rating | 2026 Rating |
|---|---|---|
| 5.7L V8, 2WD | 15/19/17 | 16/21/18 |
| 5.7L V8, 4WD | 15/18/16 | 16/20/17 |
| 5.7L V8, 4WD Z71 or Trail Boss on mud-terrain tires | 14/16/14 | 15/18/16 |
| 6.6L V8, 4WD High Country | 14/18/15 | 15/20/17 |
| 6.6L V8, 4WD ZR2 | 13/15/14 | 14/17/15 |
| 3.0L Duramax, 2WD | 22/27/24 | 23/28/25 |
| 3.0L Duramax, 4WD | 21/23/22 | 22/26/24 |
| 3.0L Duramax, 4WD ZR2 | 20/22/21 | 20/23/21 |
5.7L V8 MPG and the ZR2 Fuel Economy Loss
Among the V8s, the ZR2 posts the lowest city and highway ratings. Its 6.6L V8 returns 13/15/14 mpg, against 14/17/15 mpg for the 2026 ZR2 and its 6.2L. Because the ZR2 offers only the 6.6L or the diesel, ZR2 fuel economy depends on your engine pick. Our 2027 Silverado engine chart by trim shows which trims get which engine.
The common V8 rates lower than the 5.3L it replaces. Also, 5.7L V8 MPG is 15/19/17 in 2WD and 15/18/16 in 4WD. The highway rating falls two mpg in both. Mud-terrain tires on a Z71 or Trail Boss cut the 5.7L to 14/16/14 mpg. Our Trail Boss vs ZR2 comparison covers the other differences between the two off-road trims.
Duramax Diesel MPG and the Missing TurboMax Rating
Duramax diesel MPG stays the best in the lineup at 22/27/24 in 2WD and 21/23/22 in 4WD. The 2WD highway rating of 27 matches GM’s own estimate. GM uses it to claim more than 900 highway miles with the optional 34-gallon tank. However, the 4WD diesel loses three mpg on the highway, from 26 to 23 in GM Authority’s 2026 column. In contrast, the ZR2 diesel holds its 21 mpg combined rating, the same as 2026.
Finally, the 2.7L TurboMax has no 2027 rating yet. Our TurboMax late availability post covers which trims carry the late availability tag.
What the 2027 Silverado MPG Drop Costs in Fuel and Range
Start with gallons, then apply your local price. Over 12,000 miles a year, a 6.6L ZR2 at 14 mpg combined burns about 857 gallons. A 2026 ZR2 at 15 mpg combined burns 800 gallons. The difference is 57 gallons a year. Other setups lose between 45 and 107 gallons:
- A 6.6L High Country at 15 mpg combined uses about 94 more gallons than the 2026 version at 17.
- A 5.7L Z71 or Trail Boss on mud-terrain tires at 14 mpg combined uses about 107 more gallons than the 2026 version at 16.
- A 4WD diesel at 22 mpg combined uses about 45 more gallons than the 2026 version at 24.
At an example price of $4.00 a gallon, the ZR2 gap costs about $229 a year. The mud-terrain 5.7L gap costs about $429. Instead, use your local pump price for the real number. Fueleconomy.gov lists premium gasoline for the 6.6L and regular for the 5.7L, so price each fill-up at its own pump.
As a result, range shrinks as well. Every 10 gallons carries a 6.6L ZR2 about 150 highway miles at 15 mpg. The 2026 ZR2 went 170 miles at 17 mpg. Likewise, the 4WD diesel gets 230 highway miles from 10 gallons, down from 260. Our fuel guide for every 2027 Silverado engine covers which fuel each one takes.
2027 Silverado V8 vs. 2026 V8: Sticker and Real Driving
Owners of the outgoing 5.3L report about 19 to 21 mpg on road trips, close to the 2026 highway stickers of 20 to 21 mpg. In forum posts, 6.2L owners report 15 to 18 mpg. Also, Fuelly logs for the 3.0L diesel average 23.3 to 24.0 mpg across model years 2020 to 2024. Notably, no owner data exists for the 2027 trucks yet, so treat early real-world claims as guesses.
Owners report losing two to six mpg after moving to bigger tires or adding a lift. Silverado towing MPG falls hardest with gas V8s. Owners put them at 7 to 10 mpg with trailers near 6,500 pounds. Meanwhile, diesel owners report about 16 mpg. My read: tires and trailer weight shift your Silverado towing MPG more than the sticker gap does.
Because tire pressure moves mpg, check it before every tow. For example, the AstroAI Heavy Duty Digital Tire Pressure Gauge reads up to 230 PSI, which suits LT tires. Then the VIAIR 400P-RV compressor airs up 35-inch tires after a trail run, while it also tops off trailer tires.
Tire gear to protect mileage and towing
AstroAI Heavy Duty Digital Tire Pressure Gauge 0-230 PSI | Calibrat…
What This Means for You
If you tow often, the diesel stands out on mileage. Owners of the previous 3.0L report about 16 mpg under light to mid-weight trailers. I would pick the 3.0L Duramax for a rig you tow every month. Tow ratings do not follow horsepower, though. Chevrolet lists maximums of 13,700 pounds for the 5.7L, 12,000 pounds for the diesel and 9,700 pounds for the 6.6L. Specifically, each figure needs a specific cab, bed and package.
If you want a ZR2, the diesel returns 21 mpg combined and the 6.6L returns 14, seven mpg less. Because the diesel makes 495 lb-ft against the 6.6L’s 501, pick the 6.6L only if you value its 481 hp.
For a Trail Boss, check the tire spec first. Mud-terrain tires cost the 5.7L two mpg combined on the sticker. Chevrolet also lists 34-inch mud-terrain tires on the Trail Boss.
Final Thoughts
A one or two mpg drop sounds small, and for many drivers it is. At 12,000 miles a year it adds roughly 45 to 107 gallons. The high end works out to about nine gallons a month. I would not let a number like this talk you out of a truck you love.
The bigger choice is the engine itself. Here, the 6.6L brings the most power, the 5.7L tows the most, and the diesel wins on mileage in every setup.
Fueleconomy.gov now lists the V8 and diesel ratings, but the TurboMax still has none. So check the window sticker on the exact truck before you commit. Then match the engine to how you use the truck, not to the biggest number on the spec sheet.
FAQ
What is the 2027 Silverado MPG with the 5.7L V8?
The 5.7L V8 is rated 15/19/17 mpg in 2WD and 15/18/16 mpg in 4WD. A Z71 or Trail Boss with mud-terrain tires drops to 14/16/14 mpg.
What is the 2027 Silverado ZR2 fuel economy?
With the 6.6L V8, the ZR2 is rated 13/15/14 mpg. Pair it with the 3.0L Duramax diesel and the rating is 20/22/21 mpg, with a combined number unchanged from 2026.
What is the Duramax diesel MPG on the 2027 Silverado?
The 2WD diesel is rated 22/27/24 mpg and the 4WD diesel is rated 21/23/22 mpg. Highway mileage in 4WD falls three mpg from 2026.
Are the 2027 Silverado MPG numbers official EPA ratings?
Yes for the 5.7L, 6.6L and 3.0L Duramax. GM supplied the ratings, and fueleconomy.gov now lists the same numbers. The 2.7L TurboMax has no rating yet. Check the window sticker on the exact truck.
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