Rising diesel prices are putting pressure on pickup truck owners, but General Motors CEO Mary Barra says the company’s Duramax diesel engines can still offer lower ownership costs. Speaking during GM’s Q3 2026 earnings call, Barra argued that improved fuel efficiency can help offset higher diesel prices, raising the question of whether diesel-powered trucks can remain more economical over time.
GM Defends Its Duramax Diesel Engines
As diesel fuel becomes more expensive, GM faces questions about whether rising operating costs could discourage buyers from choosing diesel-powered pickups. During the company’s Q3 2026 earnings call, Barra maintained that GM’s Duramax diesel engines remain less expensive to own, pointing to their fuel efficiency as a key advantage.
The comparison centers on GM’s 3.0-liter LZ0 turbo-diesel inline-six, Ford’s 3.5-liter PowerBoost V6 hybrid and Toyota’s 3.4-liter i-Force Max V6 hybrid. These powertrains offer different approaches to balancing fuel consumption and ownership expenses.
Fuel Economy Gives the Duramax an Advantage
A comparison of four-wheel-drive fuel economy and 2026 base prices puts GM’s Duramax ahead of its competitors. However, the advantage over Ford’s hybrid powertrain is relatively small.
That difference matters when evaluating the potential savings from choosing a diesel truck over a hybrid. Although better fuel economy can help offset higher fuel prices, the size of the savings depends on the specific vehicles being compared and their operating costs.
Diesel Maintenance Costs Can Add Up
Fuel economy and purchase price are only part of the total cost of owning a pickup. Scheduled maintenance can add to expenses over several years, potentially changing the financial equation between diesel and hybrid models.
Diesel trucks also require diesel exhaust fluid, or DEF. Buying DEF in large containers can make it inexpensive, but it remains an additional expense that hybrid owners can largely avoid.
Which Truck Costs Less to Own?
GM’s argument has merit when the comparison focuses on fuel economy, but fuel efficiency alone does not determine the least expensive truck to own. The final cost depends on several factors, including fuel prices, annual driving distance, maintenance requirements, driving conditions and how long the owner keeps the vehicle.
As diesel prices rise, the Duramax’s fuel-efficiency advantage remains part of GM’s case for its diesel pickups. However, determining whether a diesel or hybrid truck costs less over time requires considering the full range of ownership expenses rather than fuel economy alone.
