It’s time to put the latest GM 5.3L V8 on our standard Denver 100 highway MPG test loop. Is this the most efficient V8 engine out there? How does it compare against other Silverado 1500 and Sierra 1500 engines? How does it compare to the engines in the new Ford F-150, Ram 1500, and the Toyota Tundra? Let’s dig in!
Denver 100 MPG Loop
The Denver 100 is a highway loop around Denver, Colorado. The normal loop we do is approximately 111 miles, but once in a while – we extend this loop a bit. I am driving just over 119 for this test. This way – we should get a fairly accurate reading at the pump.
The Truck
The truck we are testing is a new 2026 Chevy Silverado 1500 RST. It’s a crew cab 4×4 model with a standard bed. The 5.3L V8 produced 355 hp and 383 lb-ft of torque. The engine is mated to a 10-speed automatic transmission and a 3.23 to 1 rear axle ratio. This configuration has a towing capacity of up to 9,200 lbs.
Results and Comparisons
This truck achieved a calculated 22.85 MPG (rounded to 22.9 MPG). This is an impressive result, considering that this truck’s engine is not broken in. It can potentially get an even better results after 1,000 miles or more. This result is also significantly higher than this truck’s EPA rating of 20 MPG suggests.
- 3.0L Duramax Diesel (GMC Sierra) 31.2 MPG
- Ford F-150 Hybrid 29.6 MPG
- Toyota Tundra Hybrid 24.0 MPG
- 6.2L V8 (GMC Sierra) 23.4 MPG
- 2.7L TurboMax (GM 4-Cylinder) 23.1 MPG
If you would like to see how the Ford F-150 5.0L Coyote V8 and the Ram 1500 5.7L HEMI V8, please take a look at our previous Denver 100 MPG story.
The Verdict
I would recommend the 3.0L Duramax Diesel for those driving over 15,000 miles a year due to its superior efficiency, especially on the highway and when towing a trailer. However, for those who drive less, the 5.3L V8 may just be the “sweet spot” in the lineup over the 2.7L or 6.2L options.
Rumors suggest that GM will replace these engines in 2027 with new 5.7L and 6.6L gas V8 options aiming for better power and efficiency. We have done several video stories about this, but we are still waiting for official confirmation from Chevrolet and GMC about specs, release timing, and pricing.
