International Truck ships first on-highway vehicles with A26 engine; up to 9% fuel economy improvement
1 July 2017
International Truck has started customer shipments of its first International LT Series and International RH Series vehicles with the company’s 12.4-liter engine. The company’s internal testing shows these products are delivering up to nine percent in fuel economy improvement over the comparable models built only a year ago.
Driven by a commitment to deliver customer uptime in the Class 8 market, the A26 was developed through an initiative called Project Alpha.
Built from the proven MAN D26 engine crankcase, the in-lone, 6-cylinder A26 produces up to 475 horsepower and 1,750 lb-ft (2373 N·m) of torque from a design that’s 600-700 lbs. lighter than a traditional 15L big bore engine. Its components have been carefully engineered to deliver uncompromising uptime as well as class-leading fuel efficiency, reduced weight and quiet operation.
Utilizing a titanium compressor wheel with a simplified single-stage design, the A26 features a variable geometry turbocharger that reduces complexity and enhances reliability. Larger piston pins, connecting rods and bushings help optimize load distribution for enhanced durability, while smaller piston cooling jets increase oil pressure to improve lubrication, increasing oil change service intervals up to 70,000 miles.
The A26 is 55 pounds lighter than the engine it replaces, and also enables an impressive 200 pounds of additional weight reduction in vehicle-mounted components. Its Compacted Graphite Iron (CGI) crankcase has greater strength and fatigue resistance than traditional gray iron. Composite valve covers and shot-peened aluminum flywheel housing help deliver significant weight savings over traditional solutions.
Fuel injection pressure is maximized by the engine’s 2,500 bar (36,300 psi) high pressure common rail fuel system. Coupled with new cylinder head coolant passages that are 50% less restrictive to reduce parasitic loss to the water pump, the A26 reduces both fuel consumption and emissions.
The A26’s uniquely sculpted crankcase, which is isolated with the oil pan through a specially designed rubber gasket, absorbs vibration and reduces harshness for a quieter in-cab experience. The engine’s six-blade fan, specially designed gear teeth and calibration and programming are specifically built to reduce engine noise.