New Challenger models set records, offer more track power: Caterpillar's ACERT engines power MT700B and MT800B Series tractors.

Two of the Challenger MT800B Series track tractors have established a track record of their own as the largest tractors ever built by Challenger. The new MT865B and MT875B, rated at 510 and 570 gross engine horsepower, respectively, took tractor horsepower and performance to the highest level ever recorded in production tractors at the Nebraska Tractor Test Laboratory* (NTTL), the officially designated tractor testing station for the US, located in Lincoln, Nebraska.

The Challenger tractors set two consecutive records for the category "drawbar horsepower in an agricultural vehicle. Challenger engineers watched as both models surpassed the benchmark previously established by a competitive 4-wheel-drive tractor and witnessed the Model MT875B unofficially become the first tractor in history to pass the 500-drawbar-horsepower mark, according to Ken Huck, manager of engineering systems and test for Challenger tractors. Huck said the record is "official" after it appears in the report published by NTTL.

MT800B Series--ACERT 18.1 liter engine

"Part of the credit goes to a new 18.1-liter (1,105 [in.sup.3]) Caterpillar Tier III ACERT engine, which set its own record as the largest in a production farm tractor." said Huck. He added that the ACERT engines have advanced technology that meets this high level of compliance without sacrificing performance, durability or reliability.

In addition to turbocharging, air-to-air aftercooling and 4-valve-per-cylinder technology, ACERT engines also feature a new ADEM 4 electronics control system that enables smooth power delivery by coordinating communication between all tractor electronic control modules. Additional benefits, compared to the previous ADEM 3 system, include the ability to maintain power, even with changing fuel temperatures, improved response and reduced noise levels

Huck also credited the record-setting performance to Challenger's exclusive mobil-Trac system for its "ability to put power to the ground. He explained that part of the test involves pulling a load cart containing instrumentation that measures critical test parameters around a 0.4-mile oval test track. Additional tractors are hitched behind the cart when added load is necessary, as was the case with the MT865B.

The MT875B is available in both ag and special application versions to handle the needs of large-acreage farmers, as well as industrial and scraper operators. Customers who operate on compacted and unbroken soils will also appreciate the new special application belts that have 2.5-inch tread bars for less flexing and irregular wear. The belts are also thicker, due to two additional layers of rubber on the inner belt surface to reduce debris damage.

Cab improvements on the MT800B Series include a noticeable sound level reduction, a FOPS (falling object protective structure) built into the cab roof, and a new semi-active operator's seat with continuous real-time automatic damping force in three different positions and based on terrain inputs.

MT700B Series--ACERT C9 Engine

The three new MT700B Series tractors is powered by another ACERT Tier III diesel enginye, the C9. The C9 also combines new technology and convenience with proven traction, flotation and performance, said Tim Miller, general marketing manager for Challenger track tractors. He said use of the ACERT technology has boosted horsepower on every model of the MT700B Series, compared to the previous MT700 Series. With 537 cubic inches (8.8 L) of displacement, air-to-air aftercooling and four valves per cylinder, the C9 ACERT engine generates 225 PTO hp in the MT745B: 245 PTO hp in the MT755B; and 265 PTO hp in the MT765B.

"While most engine manufacturers resorted to other methods to meet aggressive Tier III standards, including exhaust gas recirculation, Caterpillar took an entirely different path, developing more than 250 patents in the process," said Miller. "In essence, the ACERT technology utilizes better control of the combustion process to meet emissions standards without sacrificing power."

In addition to the clean horsepower, Miller said the new MT700B Series tractors are also generous on comfort and convenience. Like the MTS00B, the cab sound level has been noticeably reduced and customer options now include a new semi-active operator's seat with for 170 mm of vertical stroke and continuous real-time automatic damping force in response to terrain inputs.

The MT700B Series' Intellitronics electronic system boasts new upgrades, from a programmable transmission for starting in any gear between one and seven to a default gear setting and selected Power Management mode, both which can be retained after shut down. The console display also includes a real-time track tension monitor that detects and displays the pressure exerted on each track belt, with an alarm that warns the operator of potential belt damage due to stretching.

* Nebraska Tractor Test

Founded in 1920, the Nebraska Tractor Test Laboratory was originally established as a standardization test to ensure the reliability of tractors sold to Nebraska farmers. The Nebraska legislature passed the law because there were more than 160 tractor manufacturers in business at the time, many of them producing undependable tractors with poor performance, and some of them over-stateing their products' horsepower.

The law was changed in 1986 to allow the sale of any tractor tested by any international laboratory approved by the Organization for Economic Cooperation and Development (OECD). The Nebraska Tractor Test Laboratory became an OECD sanctioned testing station, primarily for testing tractors built in the US--OECD codes require that tractors be tested in the country of manufacture. By 2004, twenty-eight countries were participating in the tractor test codes, with active tractor test stations in approximately 25 of those countries. Reciprocity agreements with the codes require that once an OECD test report is officially approved, it must be accepted by all participating countries.

"Despite changes in tractor design and international agreements over the years, the Nebraska Tractor Tests are still a valuable asset to North American farmers," said Tim Miller, general marketing manager for Challenger track tractors. "They provide the assurance that a company's products meet their published specifications, and it affords a direct comparison to competitive machines tested under similar conditions.

Editor's Note: Caterpillar introduced the first rubber track farm tractor, in 1987. AGCO Corporation acquired the Challen-ger line of track tractors from Caterpillar in 2002. The Challenger line includes track tractors from 225 to 570 hp (168 to 425 kW), wheel tractors from 23 to 240 PTO hp (17 to 179 kW), a family of hay equipment, and two combines.