International launches A26 heavy-duty engine
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International launches new 12.4-liter heavy-duty engine


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International Truck has launched the International A26 engine, a 12.4-liter engine for heavy-duty vehicles. Built from the MAN D26 engine crankcase, the A26 produces up to 475 HP and 1,750 lb./ft. of torque.

“The A26 was designed from the ground up to deliver uptime, durability and reliability,” said Darren Gosbee, International’s vice president of advanced engineering. “The A26 is as simple as a modern engine can be, and we’ve built uptime into every part of the development process, from design to calibration to testing.”

RELATED: Watch our test drive of the new International LT series of heavy-duty trucks.


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.

At 2,299 lbs., the A26 is 55 lbs. lighter than the engine it replaces, and also enables 200 lbs. of additional weight reduction in vehicle-mounted components. Its Compacted Graphite Iron (CGI) crankcase has greater strength and fatigue resistance than traditional gray iron, the company said.

According to International, the A26 is engineered to deliver up to 5% greater fuel economy (compared to previous ProStar specs with Navistar engines). The engine has a simplified air management system, featuring a new Variable Geometry Turbocharger, a high-pressure common rail fuel system, and new cylinder head coolant passages that are 50% less restrictive to reduce parasitic loss to the water pump.


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 sophisticated calibration and programming are specifically built to reduce engine noise.

The A26 is backed with a two-year, unlimited mile warranty, and is available for order in the International LT Series of long-haul vehicles and RH Series of regional-haul vehicles.

Fleet Equipment Magazine