What MPG does the Chevy 6.6 gas get?
In typical use, the Chevy 6.6L gasoline V8 found in Silverado HD pickups generally delivers roughly 11–14 mpg combined, with about 9–12 mpg in city driving and 12–16 mpg on the highway. Real-world results vary by configuration and workload, and towing or heavy payload can significantly lower those numbers.
Chevrolet’s 6.6L gas V8 powers heavy-duty pickups such as the Silverado HD 2500 and 3500. MPG depends on factors like 2WD vs. 4WD, crew cab vs. regular cab, bed length, and how heavily the truck is loaded or towed. The 6.6L gasoline engine is distinct from the Duramax 6.6L turbo-diesel, which has its own fuel-economy profile. The sections below outline typical ranges and practical considerations for this engine in current model years.
Typical MPG ranges for the 6.6L gas engine
Before listing the ranges, note that official EPA figures vary by model year, cab configuration, drivetrain, and bed choice. The ranges below reflect common Silverado HD configurations with the 6.6L gas V8 in recent years.
- City driving: 9–12 mpg
- Highway cruising: 12–16 mpg
- Combined (typical everyday use): 11–14 mpg
In practice, highway driving tends to edge toward the upper end of that range, while city driving and stop-and-go traffic can pull results toward the lower end. The exact numbers for your truck will be shown on the EPA window sticker for your specific configuration.
Impact of towing and payload on mpg
Before this list, it’s helpful to understand how workload affects efficiency. Towing and payload create much higher engine loads, which can dramatically reduce mpg compared with non-towing, light-duty driving.
- No towing or light daily driving (minimal payload): 11–14 mpg combined
- Moderate towing (roughly 3,000–6,000 lbs): 9–12 mpg combined
- Heavy towing (6,000+ lbs or more): 6–9 mpg combined
These figures illustrate how quickly mpg can drop when a Silverado HD with the 6.6L gas engine is tasked with moving heavy trailers or large payloads. For precise numbers, consult the EPA ratings for your exact year and configuration and consider real-world tests or on-road experiences similar to your typical use case.
Factors that influence mpg and how to optimize it
Configuration, driving style, and maintenance
Engine efficiency is affected by drivetrain choice (2WD vs. 4WD), cab and bed setup, tire size, aerodynamics, and payload. Smooth acceleration, steady cruising speeds, proper tire inflation, and regular maintenance can help maximize fuel economy within the engine’s inherent capabilities.
Additionally, the gasoline 6.6L V8 competes with a diesel option (Duramax) in the same heavy-duty lineup. While the gas engine provides strong towing capability, diesel variants typically achieve higher highway efficiency and better long-haul mileage under load. When evaluating a Silverado HD, consider how you will use the truck most often and compare the gas and diesel options accordingly.
Summary
The Chevy 6.6L gas V8 in Silverado HD models typically yields a combined mpg in the low to mid-teens under normal driving, with city efficiency around 9–12 mpg and highway efficiency around 12–16 mpg. Towing and payload can significantly reduce those numbers, sometimes pushing combined mpg into the single digits. For the exact figure, check the EPA ratings for your model year and configuration and review real-world driving reports or owner data to set expectations based on your planned use.
What is the life expectancy of a 6.6 L V8 gas engine?
When it comes to Duramax 6.6L engines, hitting over 300,000 miles or 480,000 km is often seen as high mileage, but this can vary based on maintenance and overall truck condition. With proper care, these engines can keep going strong for up to 500,000 miles or 800,000 km.
Does the 6.6 gas engine require premium gas?
87 is just the minimum they require, you can always go higher as the computers will adjust, but its not needed.
What gas mileage does the 7.3 Godzilla get?
In town I get around 10-11 mpg and highway I get around 13-high14 depending on terrain. This is on a 22 F-350 7.3 Tremor. This will probably vary depending on how you drive and also what rear-end gear ratio you have. 2021 7.3 gas 3.55 getting 16.5 at 70 mph, drops to 14.5-15 pulling a stock trailer.
What is the gas mileage on a 401 hp 6.6 L V8?
6.6L V8 Gas Engine: With 401 horsepower and 464 lb-ft of torque, this gasoline option delivers a slightly lower fuel economy, averaging around 13-18 MPG on the highway.
