Earlier this week, GM Defense announced a new $36.4 million contract awarded by the U.S. Department of State to develop a new heavy-duty Suburban for use in the Department’s Diplomatic Security Service. Now, GM Authority has learned that the new GM Defense HD Suburban will be available with both gasoline and diesel engine choices.
In a recent interview with GM Authority Executive Editor Alex Luft, GM Defense Spokesperson Angela Ambrose confirmed that the new GM Defense HD Suburban will indeed be offered with both gasoline and diesel power. Ambrose declined to provide further details on either of the engines that will be offered, but previously, GM Defense has stated that the GM Defense HD Suburban “will use significant commercial-off-the-shelf-parts,” including the “propulsion” system.
As such, it bears to reason that the GM Defense HD Suburban will offer the same engines as the commercially available twelfth-generation Chevy Suburban. That leads us to three possible engine options, including the naturally aspirated 5.3L V8 L84 gasoline unit, the naturally aspirated 6.2L V8 L87 gasoline unit, and the 3.0L I6 LM2 turbodiesel Duramax.
As for the specs when equipped in the commercially available Chevy Suburban, the 5.3L V8 L84 produces 355 horsepower and 383 pound-feet of torque, the 6.2L V8 L87 produces 420 horsepower and 460 pound-feet of torque, and the 3.0L I6 LM2 produces 277 horsepower and 460 pound-feet of torque. All three engines connect to the GM Hydra-Matic 10-speed automatic transmission.
With regard to commercial-off-the-shelf-parts, the GM Defense HD Suburban will also include familiar body, exterior, interior, and braking components. Under the skin, however, the GM Defense HD Suburban will feature “new and unique body-on-frame chassis and suspension” specifically designed to support higher payload capacity and vehicle weight, per the government vehicle performance requirements.
It’s also worth noting that the GM Defense HD Suburban will not be a Chevrolet model. Rather, it will be purpose-built for use by the U.S. Department of State to support the Diplomatic Security Service, and will not be commercially available.