2025 GMC Sierra 3500HD Diesel

While the 2025 GMC Sierra 3500HD can be had as a stripped-down base truck known as the Pro, the majority of heavy-duty Sierras leave the dealership in one of the ritzier trim levels. Indeed, the AT4, Denali and Denali Ultimate stand as the strongest evidence that the Sierra is a higher-end offering than its Chevy Silverado sibling. They offer genuine luxury with the hardcore capability of a 3500-series heavy-duty pickup.

You're shopping in an aisle with few options, and it gets even thinner considering the Chevy Silverado 3500HD is virtually the same truck apart from design, some feature content and the upper trims' interior design. The Ram 3500 and Ford's F-350 and F-450 would be your other options, and there's no reason not to consider all of them.

Different trim levels usually bring with them different feature content, interior materials, technology interfaces and, in the case of trucks, seating configurations. The Sierra HD's trim levels do that, but they are also uniquely paired with three different dashboard designs. The base Pro has the same bland dash design with subpar plastics and rinky-dink touchscreen that so underwhelmed when it was introduced as the current-generation Sierra's only interior option back in 2020. The SLE and SLT, meanwhile, share their substantially more attractive and higher-quality design with the Chevy Silverado's upper trim levels. It gets much better tech, too. Finally, the AT4 and two Denali trims get a design that's unique to GMC (though not that different) as well as an uptick in feature content and luxury finishings.