International Engines
N9 N10 N13
Cummins Engines
Cummins ISB6.7 Cummins ISX15 Cummins ISL9

THE N9 Engine

Up to 330 HP, Up to 950 ft.-lb. Torque, 2,200 RPM

The N9 is built on the same proven I-6 platform as Navistar’s legendary and industry-leading DT engine. This I-6 design grew from a big idea: bring to the mid-range diesel market traditional big bore features like wet-sleeve design and in-chassis rebuild capability. This model, which brings increased 9.3-liter displacement by longer stroke, meets the requirements of more demanding applications. The N9 adds to the reliable and durable platform premium features like dual sequential turbo technologies, single-piece gallery-cooled steel pistons, and crankcase ladder reinforcement.



Vocational Applications
The N9 is purpose-built to the needs of International customers. They are compatible with a full range of automatic and manual driveline options and thousands of potential build configurations to serve the broadest range of on- and off-highway applications. Ratings offer up to 330 hp and 950 lb.-ft. of torque. Shift energy management technology allows for higher peak torque when used with select transmissions.
Excellent Power
N9 engines use dual sequential turbochargers to deliver powerful performance for any job. The smaller, primary turbo responds quickly for immediate take-off at low engine speeds, and the larger, secondary turbo provides peak power at higher speeds and on steep grades. Equipped with Dual Fixed Geometry turbochargers in series means:
  • Less moving parts and complexity for more reliable performance
  • Wastegate prevents high bearing loads and overboost
  • Excellent throttle response

The N9 also features full power off idle, strong launch performance with first high pressure turbo, second low-pressure turbo provides high air flow for consistent highway speed and fewer moving parts means lower cost of replacement than VGT and sliding nozzle turbo. The electro-hydraulic high-pressure fuel system features new high-efficiency injector nozzles and advanced electronic control strategies for fuel economy gains.

A rock-solid, time-tested platform ensures legendary reliability. For the new generation, Navistar engineers carried forward the proven technologies and components like:
  • Premium plateau-honed cylinder design
  • Reinforced bearing-cap ladder
  • Durable roller cam followers

For changes outside the base engine design, the intention was to further improve reliability. Foremost among these changes are dual sequential free-wheel turbochargers and a premium wiring harness, which utilizes a single foam-molded design that locks down wiring and secures connections.

The N9 features the same precision-machined wet-sleeved design that provides heavy-duty engine durability. Six bolts per cylinder provide headgasket integrity unmatched by competitive four-bolt designs. Premium valvetrain components and low-friction design further increase engine life. Adding to the appeal of this engine is its ability to be completely re-built in-frame. As a result, the engine can be returned to original factory specifications for a lot less than the cost of remanufacturing, which gives them a strong value advantage at re-sale. Over the past 10 years, the average residual value of N-powered International medium-duty trucks has outpaced the competition by 12–19 percent.


Engine Type
Diesel, 4-Cycle
Inline 6 Cylinder
9.3 L (570 cu. in.)
Bore & Stroke
4.59 in. & 5.75 in.
Compression Ratio
Two-Stage Turbochargers, Intercooler & Aftercooler
Combustion System
Direct Injection
Engine Lubrication
30 Quarts
Total Engine Weight
1,425 lbs
L 45 in. x W 42 in. x H 47 in.
4 Valves per Cylinder
350 Design Life
550,000 miles
Change Engine Oil/Filter
Up to 25,000 miles
Replace Fuel Filter
30,000 miles
Replace Coolant
300,000 miles


If you’ve got a job to do, International® DuraStar® will help you get it done. That’s because in the world of medium-duty trucks, DuraStar is the one truck that has always delivered. It goes beyond efficiency, durability and driver satisfaction. DuraStar also has a well-earned reputation for adaptability, an ability to handle just about any task. Whether it’s towing cars off the highway in a snowstorm, repairing downed power lines, or racing to a fire, DuraStar is a rugged performer that always answers the call. The success of your business depends on a truck that performs efficiently. Which is why DuraStar® was designed from the ground up to run effectively, for maximum productivity.

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No matter what you throw at it, there’s just no stopping WorkStar.® With the broadest range of available powertrain options, it can muscle its way through even the heaviest loads and the most rugged jobs. Couple that power with an electrical system that offers body control functionality and more efficient diagnostics, and you’ve got a truck with the brains and brawn to keep your business running at its best. Huck-bolted frame and crossmember system designed for maximum vocational durability with a number of frame-rail options.

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