| Engine | 5.3L 8-cyl |
| Transmission | Automatic 6-spd |
| Drive | Rear-Wheel Drive |
| Fuel Type | Regular Gasoline |
| Vehicle Class | Special Purpose Vehicle 2WD |
| Engine Desc | SIDI |
| Start-Stop | No |
| EPA Vehicle ID | 37669 |
17 MPG combined won’t win any fuel efficiency awards, but for the 2017 GMC Sierra C15 Cab Chassis 2WD with the 5.3L V8, it’s a number that’s simply part of the job. This truck isn’t designed for grocery runs or soccer practice; it’s a workhorse, a blank canvas ready to be upfitted into a plumber’s service vehicle, a landscaper’s flatbed, or a small business’s mobile workshop. Its fuel consumption is a necessary overhead for what it offers.
City and highway performance
The EPA estimates of 15 MPG in the city and 20 MPG on the highway reflect the realities of driving a vehicle like this. Stop-and-go city driving, often with a payload, puts a strain on the 5.3L V8. The six-speed automatic transmission works to optimize fuel economy, but the engine’s inherent thirst becomes apparent in urban environments. On the highway, with consistent speeds and less frequent acceleration, the Sierra C15 can stretch a gallon a bit further. Reaching that rated 20 MPG requires conscious effort; resisting the urge to accelerate aggressively is critical, especially when the chassis is unladen. These figures are tested without any upfit, so in the real world, expect these figures to vary based on how the vehicle is configured.
Annual fuel cost
The EPA estimates an annual fuel cost of $2,600 for the 2017 GMC Sierra C15 Cab Chassis. This figure is based on driving 15,000 miles per year and using national average fuel prices. Of course, this is an estimate, and your actual fuel costs will depend on how many miles you drive, the type of driving you do (city versus highway), and the price of gasoline in your area. For businesses operating this vehicle, fuel costs should be factored into budgets and pricing models. Considering all Gmc fuel economy data can give buyers an even more clear picture of other vehicles in the lineup.
Real-world expectations
Experienced owners of work trucks like the Sierra C15 understand that EPA estimates are a starting point, not a guarantee. Loaded with equipment, tools, or materials, and driven by different employees with varying driving habits, real-world fuel economy can easily dip below the stated figures. Terrain plays a significant role too; hilly routes will demand more power, thus reducing fuel efficiency. Conversely, flat highways with consistent speeds provide the best opportunity to approach the EPA’s highway estimate. Fleet managers and business owners closely monitor fuel consumption, often using telematics systems, to identify inefficiencies and optimize driving habits.
How it compares
Direct competitors to the Sierra C15 Cab Chassis include the Ford F-150 XL Regular Cab Chassis and the Ram 1500 Tradesman Cab Chassis. The Ford, equipped with its 3.5L V6, achieves a slightly better EPA-estimated combined MPG of 20. However, the GMC’s reliable V8 might be preferred by those who prioritize towing capacity and raw power over marginal fuel savings. The Ram 1500 Tradesman, with its 3.6L V6, mirrors the Ford’s economy. The choice often comes down to brand loyalty, specific upfitting requirements, and dealer relationships, as the fuel economy differences are often viewed as negligible compared to the vehicle’s utility. The SIERRA MPG across all years offers further insight into generations and models.
Tips to maximize efficiency
Aggressive acceleration is the enemy of fuel economy, especially in a truck. Smooth, gradual acceleration allows the engine to operate more efficiently. Anticipate traffic flow and maintain a consistent speed whenever possible. Avoid unnecessary idling; idling consumes fuel without covering any distance. If you’re stopped for more than a minute, it’s generally more efficient to turn off the engine and restart it.
Proper tire inflation plays a crucial role in fuel efficiency. Check your tire pressure regularly and inflate your tires to the recommended pressure, which can be found on the doorjamb or in the owner’s manual. Underinflated tires increase rolling resistance, which reduces fuel economy.
Regular maintenance is essential for optimal fuel efficiency. Ensure that your engine is properly tuned, and that air filters, spark plugs, and other components are replaced according to the manufacturer’s recommendations. A well-maintained engine runs more efficiently and consumes less fuel.
Reduce unnecessary weight; extra weight increases fuel consumption. Remove any tools, equipment, or materials that are not needed for the current job. Consider lighter materials for upfitting when possible.
Consider the use of aftermarket fuel economy technologies. While results can vary and should be weighed carefully against cost, some owners use performance tuners that unlock more efficient engine operation or install aerodynamic aids that minimize drag. Conduct thorough research before investing in any aftermarket modifications.