Horsepower unmatched by today's ag tractors and the most versatile design in the industry headline the all-new Challenger MT800 Series tractors.

Four models, ranging from 340 to 500 gross engine horsepower, stretch the limits on productivity and performance in the high-horsepower tractor category. These new machines are built on legendary track technology with advancements in comfort, power and speed.

The largest tractor in the series, the Challenger MT865, offers the highest horsepower of any production tractor — track or wheel. Powered by a 964-cubic-inch (15.8L) Cat C16 engine, the MT865 is rated at 500 gross engine horsepower. Matched with a belted ag tractor's ability to put a higher percentage of the engine's power to the ground, this tractor will offer farmers unprecedented pull and ability to get work done.

“This tractor gives farmers the ability to pull wider tools and bigger seeding units to increase their overall efficiency,” says Brian Foster, senior marketing consultant. “Customers have been asking for this kind of power and this tractor delivers.”

The Challenger MT800 Series is the first in its size class to offer adjustable track gauge. The exclusive Mobil-trac system undercarriage design allows the distance between the tracks to be infinitely adjusted between 90 and 128 inches (2286-3251 mm) to optimize the tractor for a wide variety of tillage and row-crop applications. The new in-line reaction arm allows for quick, easy gauge changes that can be made without spacers and without detensioning the belt.

The MT800 Series also offers the longest wheelbase of any two-track design in the industry, for maximum balance, flotation and tractive efficiency. New suspended mid-wheels improve traction and ride in uneven field and road conditions. A larger rear drivewheel allows for excellent crop clearance, as well as improved belt-to-driver grip.

The widest variety of undercarriage options adds to the overall versatility of the MT800s. Belts are available in four widths, from 18 to 36 inches (457 - 914 mm), and in two types. Two idler, mid-wheel and driver widths are offered to improve belt life, allow for use of narrow belts in row crops, and improve belt-to-driver performance.

“Because of the versatility of this design, a farmer can use this tractor for a wider variety of jobs. With a simple change of belts and track spacing, the MT800 can go from tillage operations to in-row applications,” Foster says. “Tractor utilization is improved, and overall owning and operating costs can be reduced.”

When it comes to the demands on hydraulics, the Challenger MT800 Series tractors answer with standard 43.5 gpm (166 LPM) flow, and four standard remote circuits. An optional 59 gpm (223 LPM) pump is available, as well as two additional remote hydraulic valves for a total of six. The exclusive Load-Independent Flow Division (LIFD) insures proportional oil flow to all circuits when the system is operating at maximum capacity, resulting in smooth, coordinated operation of every function.

To further augment versatility, three drawbar types are available for MT800 tractors. This includes a first-of-its-kind optional controlled drawbar, which uses hydraulic cylinders to control its position or dampen the drawbar when un-pinned. The standard tractor is equipped with a wide-swinging roller drawbar, with plus or minus 32 degrees of swing. Tractors equipped with an optional steerable 3-point hitch come with a free-swinging drawbar that offers plus or minus 28 degrees of swing from the centerline.

The optional 3-point hitch for the MT800 tractors is an exclusive steerable design with 19,500 lb. (8845 kg) of lift capacity. The steerable hitch is tied into the steering and improves tractor steering control and row corrections, especially advantageous in narrower gauge applications.

To keep farmers in the field longer, the MT800 Series tractors offer a standard 305-gallon (1155 L) fuel tank. By adding an optional center tank, fuel capacity can be increased to up to 330 gallons (1249 L). The MT865 comes standard with a 330-gallon (1249 L) fuel tank. Moving between fields becomes more efficient as well, with a top transport speed of 24.6 mph (39.6 km/hr).

The Challenger MT800 Series tractors are powered by Caterpillar engines, and use Cat's proven mechanically actuated, electronically controlled unit injectors and air-to-air aftercooling (ATAAC). Challenger MT835 and MT845 tractors use the Cat C12 engine to achieve 340 (254 kW) and 380 (283 kW) horsepower, respectively. The MT855, rated at 450 horsepower (336 kW), is powered by the Cat C15 engine. A Cat C16 engine gives the Challenger MT865 industry-leading 500 horsepower (373 kW).

The Challenger MT800 Series tractors' powertrain integrates many proven components into the new design. The 16F/4R Caterpillar designed transmission offers nine gears in the critical 3.4 to 9.3 mph (5.8 to 14.9 km/h) working range. The broad operational range allows the tractor to adapt to changing conditions without sacrificing performance.

Linking the entire tractor together is an innovative electronic management system. The Intellitronics network enables the engine to communicate with the entire powertrain for smooth shifting, optimum power management and the most efficient use of fuel. The optional ISO11783 electronics system allows Challenger MT800 Series tractors to recognize and communicate with implements for coordinated operation.

The Challenger MT800 Series cab offers excellent space, visibility and comfort. The spacious cab boasts 108 cubic feet (3.06 m3) of cab volume surrounded by 67.5 square feet (6.2 m2) of glass. An exclusive Surround-Flow ventilation system directs air through strategically placed vents and ducts for maximum airflow and consistent cab temperature. Optional climate control helps maintain a comfortable interior temperature, regardless of changing conditions outside.

The optional Nightbreaker HID lighting system improves visibility at night, and under adverse weather conditions. A walk-around platform provides easy access all around the outside of the cab for fueling, adjusting lights for varying implements, or cleaning.

The Tractor Management Center (TMC) includes the TMC display and controls for the transmission, hydraulics, throttle, 3-point hitch (optional), PTO (optional), and a roading lockout switch, as well as an integrated armrest. The TMC rotates with the operator seat for easy access and maximum visibility. The TMC display provides the operator with basic tractor performance data and diagnostic information from the Intellitronics system.

The new Opti-Ride suspension increases productivity by offering a smooth ride at top field and transport speeds. The chassis is isolated by two large rubber/fabric springs. Additional rubber cushioning material added to the driver, mid-wheels and idler further enhances the ride.

“Like the Challenger MT700 Series tractors introduced in the fall of 2001, the MT800s were designed from the start to include innovations and technologies that improve overall performance,” says Foster. Examples include electronic control modules throughout the tractor that share performance data via the Intellitronics network. This allows the tractor to monitor and diagnose performance, program repetitive tasks and interface with various GPS-based systems, including guidance controls.

The One-Touch management system allows the operator to record a series of functions, and then repeat the series on command. One-Touch control can automate a sequence of events such as transmission shifting, throttle, 3-point hitch position, PTO status, implement raise and lower functions and automatic guidance.

An optional Auto-Guide satellite guidance system steers the tractor when making parallel swaths. The system uses GPS technology and provides multiple levels of accuracy, ranging from less than one meter to less than one inch. “The key benefits of this system are improved efficiency and reduced operator fatigue,” Foster explains. “The operator can focus more attention on implement performance and gain the benefits of reduced over-lap or under-lap.”

Challenger MT800 Series tractors will be available from Caterpillar dealers beginning later this year. For more information, contact your local Caterpillar dealer or log on to www.Cat-Ag.com.