Video: MPG Surprise – How Far Will The 2024 GMC Sierra AT4X AEV Diesel Go on a Fill-Up?

The 2024 GMC Sierra AT4X AEV used in this video comes with a 3.0L I6 diesel, which is great for range.

For those of you wondering how a base model engine behaves in the 2024 GMC Sierra AT4X AEV, it is remarkably capable. Remember: TFL Truck adores the 3.0 inline six-cylinder turbo-diesel that GM built. It’s arguably one of the better powertrains they’ve produced in recent years.

This is a new option with 305 hp and 495 lb-ft of torque that is mounted to a 10-speed automatic. This diesel powertrain was recently updated to produce more power, better economy, and better durability. The Duramax turbo-diesel is preferred by about 20 percent of the buyers, according to (this) article.

Other than the AT4X upgrades in lockers, axles, suspension, and rolling stock – the AEV package adds armor, an updated interior, and a unique tire and wheel package. Now that it has a torquey, thrifty diesel, it may become an iconic overloading rig.

Why is Andre doing an MPG test with the 2024 GMC Sierra AT4X AEV?

We already know that the regular Silverado and Sierra with this powertrain is extremely efficient. Even the older version, packed inside a GMC Yukon, performed much better than the EPA’s data. While the regular 4×4 Sierra with the Duramax diesel gets 24 mpg combined, the AT4X is rated at 19 mpg combined. Remember: the AT4X has larger tires, heavier wheels, and front/rear lockers. It also has the DSSV Multimatic spool-valve shocks. That’s a lot of extra drag to lug around.

So, what happens when you add tons of armor and goodies to this trim?

Right off the bat, Andre draws your attention to the door’s sticker. It indicates that the payload is down to 1,048 lbs. That’s miserable for a full-size truck. To put it another way, the tiny Hyundai Santa Cruz can haul about 400 lbs more. It can tow up to 8,500 lbs, which is “meh.” That deficit is based on the weight the vehicle has to contend with. Remember all that armor and the heavy diesel? Yeah, between that and the heavier wheels and tires – you’ve got a heavy truck.

During the trip, Andre reviews the ride and handling of the truck, and that includes the performance of the turbo-diesel. It was just a 57-mile trip, but it was on mountain roads and highways (climbing up towards Big Sky ski resort). He was somewhat surprised by the feedback. Watch the video and you might be surprised as well!

Nathan Adlen
Easily amused by anything with four wheels, Nathan Adlen reviews vehicles from the cheapest to the most prestigious. Wrecking yards, dealer lots, garages, racetracks, professional automotive testing and automotive journalism - Nathan has experienced a wide range of the automotive spectrum. Brought up in the California car culture and educated in theater, childhood education, film, journalism and history, Nathan now lives with his family in Denver, CO. His words, good humor and video are enjoyed worldwide.