GMC duramax diesel mpg and fuel efficiency

Your GMC vehicle is engineered for fuel efficiency, power, and performance. When it comes to diesel mpg, GMC offers vehicles with superior efficiency.


Savana uses a Duramax 6.6-liter V8 direct injection turbo diesel engine. The Savana Cargo van gets 12 mpg in the city and 18 mpg for highway driving. Duramax diesel engines are biodiesel-capable and come with an Allison transmission. The 2013 Savana passenger van is rated at an estimated 13-mpg city and 17-mpg highway.


The 2013 Sierra 2500HD Denali and 2013 Sierra 3500HD Denali both get a combined average of 18 mpg highway, which is consistent with the 2012 rating for the Sierra 2500HD Denali, which received a combined 18 mpg.


Diesel has a higher energy density than gasoline. Energy density is the amount of energy stored in a substance, and is rated in British thermal units (Btu) or joules (J). One gallon of diesel has 147,000 Btu. In comparison, one gallon of regular grade gasoline contains 125,000 Btu.

Technology makes the Duramax engine both powerful and fuel efficient. Direct injection with 30,000 psi turns diesel fuel into a fine mist, which makes for a faster and cleaner burning diesel fuel. The 6.6-liter V8 engine can produce 765 lb-ft torque and 397 hp.

When direct injection is combined with a turbocharger, the engine produces even more power with no reduction in efficiency. Turbochargers do not require energy from the engine, so no power is lost. The turbocharger is controlled by an increase in engine speed and the exhaust gas pressure.


Diesel engines are designed to last and may require less maintenance. To keep your GMC running at peak performance, have the oil changed at regular intervals. Diesel fuel produces soot from combustion. Keeping the oil clean also keeps the engine clean. The engine will perform at its best and give you the longevity you expect from your GMC vehicle.

Engineering improvements include more than just diesel mpg. Your vehicle has more power and acceleration with improved starting in cold weather. You want a professional vehicle that meets all of your requirements. GMC's professional-grade engineering gives you that and more.