The TurboMax Engine

Introduction to the TurboMax

In 2019, General Motors tried out a new technology that was a bit controversial at first. They swapped out their tried-and-true base engine for something called a TurboMax. From 2014 through 2018, the base engine in the Chevy Silverado 1500 and the GMC Sierra 1500 was a 4.3-liter V6. That engine was replaced in 2019 with a new turbocharged 4-cylinder called the L3B, which would later be rebranded as TurboMax.

Four cylinders in a work truck? You can see why the move was controversial at the time. But the engineers had designed the new engine so well that it outperformed the V6 in both horsepower and torque. Let's dive under the hood and see what sets the TurboMax engine apart from the older technology.

TurboMax Engine Specs

Here's a head-to-head match-up of the power delivered by the TurboMax engine and the V6 it replaced:

Despite having a 1.6-liter deficit in displacement, the turbocharged inline-four engine delivered a boost of 25 horsepower and 125 lb-ft of torque over GM's V6 engine. The TurboMax would have been a failure in the eyes of GMC truck buyers if it had underperformed the engine it was built to replace. In just one example of its performance, the 2025 GMC Canyon Denali trim can rush from 0 to 60 miles per hour in just 6.8 seconds when propelled by the TurboMax engine.

The TurboMax delivers impressive power for any work truck

GM Engine Comparison

The TurboMax engine clearly outperforms the V6 engine it replaced. Here's how it stacks up against the larger V8 engines that are available in GMC Sierra trucks.

The V8 engines have more horsepower than the TurboMax, which is important for vehicle acceleration. However, torque is the more important factor if you plan to haul or tow things with your work truck. The TurboMax delivers 47 more lb-ft of torque than GM's 5.3-liter V8, and it delivers only 30 less lb-ft than the 6.2-liter V8.

TurboMax Fuel Efficiency

Another area where TurboMax engines excel is in fuel efficiency. When equipped with the inline-four TurboMax, a rear-wheel drive 2025 GMC Canyon delivers an EPA-estimated 23 mpg in highway driving and 19 mpg in town. When equipped with four-wheel drive, it delivers 22/18 in highway/city driving. This definitely outperforms the older V6 engine that the TurboMax replaced.

GM's 5.3-liter V8 can deliver 22 mpg on the highway, but the efficiency drops to 16 mpg in city driving. The 6.2-liter V8 engine drops the fuel efficiency to 20 mpg on the highway and 15 mpg in the city. You can see how the TurboMax engine is going to save you a lot of money on your monthly fuel bill.

The TurboMax offers excellent fuel economy for a work truck

TurboMax Tow Capacity

When equipped for towing, the 2025 GMC Sierra 1500 is rated to pull 9,500 pounds. The older 4.3-liter V6 engine that the Sierra was equipped with before 2019 was only rated to tow 7,600 to 7,900 pounds, depending on the drivetrain and configuration. The increased torque provided by the TurboMax engine allows you to tow nearly a ton of additional weight.

The TurboMax delivers impressive towing capability

TurboMax Engine Durability

The inline-four TurboMax is clearly a technological advancement when it comes to engines. But is it built to last?

The TurboMax is built with a forged steel crankshaft, an aluminum block, and a forged bottom end. It was designed to sustain heavy use over time. However, there are some factors with the TurboMax to keep in mind, especially if you're using it as a light-duty work truck.

Direct injection engines like this one can experience carbon buildup over time. When towing or hauling heavy loads, the TurboMax can use more oil than expected. Like any other vehicle, a GMC truck equipped with a TurboMax engine is going to take good care of you, if you take good care of it. Regular oil checks and turbo cooldowns should be a part of your regular maintenance schedule to prolong the life of your truck.