NASHVILLE. Calling it “as simple as a modern engine can be,” International Truck on Monday launched the International A26 engine, a new 12.4-liter diesel designed to provide industry-leading reliability to the Class 8 market.

Speaking from the exhibit hall at the TMC annual meeting here, Bill Kozek, president, Truck and Parts, explained that the A26 is the company's latest product engineered with a focus on customer uptime. The engine was developed through an initiative called Project Alpha, which brought together a new team of top powertrain engineers. The initiative pursued a fresh approach that emphasized simplicity over complexity and using only proven components.

“Project Alpha has fundamentally changed how we design diesel engines,” Kozek said. “The International A26 has been designed to address the rigorous demands of Class 8 truck customers. It’s been tested to extremes and meets a demanding B10 design life standard for an unprecedented 1.2 million miles.”

Built from the proven MAN D26 engine crankcase, the A26 produces up to 475 horsepower and 1,750 lb.-ft. 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, explained Darren Gosbee, vice president, Advanced Engineering.

“The A26 was designed from the ground up to deliver industry-leading uptime, durability and reliability,” said Gosbee. “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.”

As presented by Gosbee:

Every component is engineered to maximize uptime. 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 pounds, the A26 is the lightest engine in its class.  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 impressive weight savings over traditional solutions. 

The most efficient engine offered in International’s on-highway lineup.  Engineered to deliver up to 5% greater fuel economy, the A26 has a simplified air management system, featuring a new Variable Geometry Turbocharger. 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.  

Quietest engine in the lineup. 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 warranty of two years, unlimited miles. The warranty reflects confidence in the engine’s reliability and durability, which have been confirmed through extensive validation and testing process, the company says. This includes:

  • Hundreds of thousands of hours of “key life” and dyno testing at extreme engine speeds and loads.
  • Millions of real-world test miles over the harshest North American roads, including high altitudes and temperatures as low as -40° F.
  • Full validation cycles (concept, design, statistical and product validation) over a period of years to identify, correct and retest any issue.

The A26 engine is available for order in the International LT Series of long-haul vehicles and RH Series of regional haul vehicles. Production will begin in April, and delivery in the LT will follow in May.