What's The MPG Of An EcoTec3 5.3L V8? Here's What Drivers Say

General Motors' EcoTec3 5.3L V8 engine is known for its dependable power and solid towing capabilities. The Chevrolet Silverado and Suburban, as well as the GMC Sierra and Yukon, are all equipped with the motor, making it a popular choice for buyers.  But for drivers interested more in fuel efficiency, the engine's overall performance may not be as apparent. While Chevy estimates are available, real-world driving conditions may not always match up. So, what are drivers saying about the EcoTec3?

In a 2024 Reddit thread on "2023 Chevy Silverado 1500 LTZ 5.3L V8 10-speed MPG," one user reported 14 miles per gallon (mpg) in city driving and 23 mpg on the highway. In this case, the truck's fuel efficiency seemed more consistent at steady speeds during longer highway trips. That was echoed by another user, who reported slightly lower city mileage while consistently getting over 20 mpg on the highway. Overall, these numbers are close to the ones from Dale Earnhardt Jr. Chevrolet, which lists the EcoTec3 5.3L at 16 mpg city and 22 mpg highway. It's also right in line with the EPA, which lists the Silverado at 15-16 city and 19-22 highway.

It's important to note, however, that miles per gallon can be affected by a variety of different factors. Aggressive driving, cold weather, and hauling extra weight are just some of the things that can decrease mpg, giving the vehicle less than optimal performance.

Chevrolet's EcoTec3 5.3L V8 is valued for its towing capacity and power, but when it comes to mpg, it's not exactly overachieving at 14-16 city. However, on the highway, the EcoTec3 gets around 22-23 mpg. So what's a more ideal option for gas mileage, and is it better than GM's engine overall?

In a 2023 Reddit discussion on "3.0 Duramax vs 5.3 v8," one user decided to go with the 3.0L Duramax over the EcoTec3 in the GMC Sierra, praising its smooth operation and impressive fuel economy. Another driver agreed, stating they got 22 mpg in the city and 30 mpg on the highway. The EPA's numbers of 23 mpg in the city and 29 on the highway reinforce both claims. But while the 3.0L's mpg was impressive, there was definitely a difference in power, which made the choice easy for one user. "Test drove a 3.0 when they first came out. Not enough power for my liking. 5.3 will get up and go." Evidently, the EPA's 5.3L Sierra numbers of 16 city and 20 highway weren't always a dealbreaker versus the less powerful 3.0.

In the end, if mpg is the determining factor for drivers, there are better options available than the EcoTec3 5.3L V8. But for those not wanting to sacrifice power and towing capacity, dealing with fewer miles per gallon probably isn't much of an issue.