What's the Future of Mediim-Duty Truck Engines?
International TerraStar 4x4 Named Medium-Duty Truck of the Year
The Class 4-5 medium-duty truck features an Allison Optimized 1000 transmission, Fabco TC-28 gear-driven transfer case, and Diamond Logic electrical system.

The 2014 Medium-Duty Truck of the Year was first introduced in 2010 as a 4x2 version. The 4x4 model was introduced at the 2013 Work Truck Show, winning the prestigious truck of the year award just one year later.
Photo: International
The InternationalTerraStar 4x4 was selected as Work Truck magazine’s 2013 Medium-Duty Truck of the Year. The award was presented March 5 at the 2014 NTEA Work Truck Show in Indianapolis.
Twelve vehicles were included in an online ballot and voted on by professional fleet managers, who were asked to consider which medium-duty truck model best fit their fleet requirements, including application effectiveness, durability, quality, servicing, maintenance, and lifecycle costs.
The Class 4-5 TerraStar 4x4 provides frame rail strength of 80,000 psi, a commercial-duty Allison Optimized 1000 Series transmission, a Fabco TC-28 gear-driven transfer case, and a five-year unlimited mile warranty.
Michael Cerilli, vice president of marketing for Navistar, accepted the award during a presentation at the Work Truck Show.
“We’re honored for TerraStar 4x4 to be named Work Truck magazine’s Medium-Duty Truck of the Year by fleet managers throughout our industry,” Cerilli said. “International Trucks have long been recognized as a leader in the medium-duty class, and now to be recognized in the Class 5 segment is rewarding.”
Navistar launched a truck configurator for the TerraStar (in addition to the ProStar and DuraStar) in January, allowing customers to design, build, and customize the truck’s cab, exterior, interior, and powertrain on its website.
Launched in 2010 in a 4x2 configuration, the International TerraStar took center stage giving work truck buyers a new product with a wide range of commercial-duty features. Now, the 4x4 enables International Truck to capitalize on the other half of the market, so TerraStar is poised to win over an even broader range of customers.
“The TerraStar is the smaller sibling to the DuraStar, the best-selling medium-duty model throughout the past two decades, leveraging the same platform and commercial grade components,” said Bill Kozek, Navistar’s president, North American Truck and Parts. “The TerraStar shares the same rugged, durable and hardworking DNA, making it in a class unto itself. The TerraStar 4x4 will deliver additional commercial duty capability for a wide range of customer needs, including construction, utility, landscape, and other off-highway applications.”
Powering the Medium-Duty Powerhouse
At the heart of the TerraStar 4x4 is its 300 hp, 6.4L V-8 engine, delivering 660 lb.-ft. torque. This engine features a compacted graphite iron (CGI) block, which offers high strength without added weight, according to the manufacturer.
With 38-percent more visibility and 30-percent more cab interior space than the competition, the TerraStar also offers enhanced maneuverability for tight work environments, according to the manufacturer. The 4x4 features 11-inches of additional headroom and is 8-inches wider than its closest competitor.
In addition, the commercial grade TerraStar cab, available in extended cab or crew cab configurations, is designed to be extremely durable and is constructed with double-sided, galvanized high-strength steel protected by a five-step, professional-grade coating process to resist corrosion.
The TerraStar includes the International Diamond Logic electrical system. With Diamond Logic, the engine, transmission, instrument panel, and other vehicle components continually communicate with each other electronically. By monitoring critical vehicle functions and relaying information to the driver in real-time, Diamond Logic ensures safe, efficient vehicle operation.
Diamond Logic delivers a number of customizable features for added convenience and safety, such as automated pre-trip inspections, headlights on with wipers, automatically engaged safety interlocks, programmable switches, and more, depending on the application.
The TerraStar 4x4 is designed to last twice as long as the pickup truck platforms offered by competitors, according to the manufacturer. Its huck-bolted cross-members deliver best-in-class framerail strength of 80,000 psi, a commercial-duty Allison Optimized 1000 Series transmission for maximum power output, and a Fabco TC-28 gear driven transfer case — the only gear driven transfer case in the market.
Fabco is an industry leader in all-wheel-drive transfer cases and steer drive axles for medium- and heavy-duty vehicles, according to International. The forged helical gearing and roller bearings give high torque and horsepower capacities while offering a quiet and smooth driving experience. A precision, cast iron housing offers rugged durability with optimized weight.
Mated to the 6.4L V-8 engine, the Allison Optimized 1000 Series transmission features shift energy management (SEM), load-based shifting scheduling (LBSS), and automatic “neutral.”
More Vehicle Research

NTEA Adds Future Truck Summit to Work Truck Week 2027
NTEA is replacing the long-running Green Truck Summit with something new: Future Truck Summit. The event, in collaboration with NAFA Fleet Management Association, is scheduled at the start of Work Truck Week 2027, March 9–12.
Read More →
Ford Fathom Production Takes Shape at Louisville Assembly Plant
Ford is rebuilding Louisville Assembly Plant around an entirely new EV manufacturing process. Here’s how the Universal EV Production System will change the way the Ford Fathom midsize electric truck comes together.
Read More →
Second-Quarter 2026 Commercial Vehicle Data Signals Key Shift in Fleet Turnover and Market Velocity
Work Truck Solutions’ Second-Quarter 2026 Commercial Vehicle Market Analysis reported positive indicators suggesting fleet managers are now rotating aging units, relieving pre-owned inventory friction as business owners move quickly to secure assets.
Read More →
EV Fleet Reality Check: What Operators Wish They Knew Before Electrifying Their Work Vans
Electric work truck upfits bring new compatibility questions. Learn how parts availability, OEM guidance, power demands, and route planning can affect fleet performance.
Read More →
Ford Unveils Name for Under-$29K Midsize Electric Truck
Ford has unveiled the name of its new midsize electric truck: Fathom. It will have a starting MSRP of $28,350, and preorders will begin in early 2027.
Read More →
DTNA Plans to Build New U.S. Manufacturing Facility
Daimler Truck North America plans to build a new, state-of-the-art manufacturing facility in the United States to strengthen its production capabilities across North America. The location has not been disclosed.
Read More →
Recalls You Need to Know About in August 2026
If you have Altec, Autocar, Chrysler, Daimler Truck, Ford, Heil, International, Orange EV, Paccar, Shyft Group, Volvo Trucks, or Wabash vehicles in your fleet, you should check these important recalls issued by the National Highway Safety Administration.
Read More →
DTNA to Close Portland Facility, Move Manufacturing to the Carolinas
Daimler Truck North America will shift production of the Western Star X-series, Freightliner eCascadia, and Freightliner eM2 from its Portland, Oregon, manufacturing facility to its manufacturing operations in the Carolinas.
Read More →
Kenworth T880: Powertrain & Customization Options
Vocational fleets often require trucks tailored to specific applications, and the Kenworth T880 is designed with flexibility in mind. In this video walkaround, Rachel Woods explains how the T880 can be configured to support a broad range of industries and operational requirements.
Read More →
Electrification Incentives: The Acquisition Windfall Fleets Can't Miss
Discover how fleets can use tax credits, grants, rebates, and vouchers to dramatically reduce electric truck and charging infrastructure costs—before today’s funding disappears.
Read More →

