New Engines, New Looks Included in '07 Trucks

Sept. 28, 2010

Motor vehicle model years usually start in the spring or summer preceeding the calendar year for which they're named. Thus, 2007-model vehicles are already being built, but manufacturers will put a new batch into production beginning in January. These get the '07 diesels described in Are You Ready for January '07 Engines?. The trucks have been re-engineered to accommodate the new engines, and many have undergone extensive studies and tests on underhood airflow as a way to help cooling systems remove excess heat from cylinder blocks and accessories.

High heat levels — sometimes measured at hundreds of degrees — began being a problem as diesel operating temperatures climbed so they could burn cleaner. The problem became acute with diesels made to meet the October '02 deadline, and suppliers had to devise more robust materials for hoses and wiring, and accessories like alternators and fluid bottles for windshield wiper washers. Many '07 diesels will run even hotter, so some trucks will get bigger radiators to handle the heat and wider frame rails to mount them.

Some manufacturers have turned the engine situation into an opportunity to restyle exteriors and upgrade interiors. Some changes are easily spotted and others are subtle. But given the extensive work and money invested in them, they are different enough to merit being set apart from what came before. Perhaps we should call them "07-1/2"models. Anyway, here are succinct descriptions of the upcoming Class 8 vehicles.


Freightliner's FLD is gone as a highway tractor, but thanks partly to a long-running military contract, an SD (severe-duty) version (shown) remains. It's supplemented by a Business Class M2V (for vocational) model, which includes a Class 8 variant. Freightliner's own 14-liter Detroit Series 60, with ratings of 455 to 515 horsepower, is standard in most long-hood trucks and tractors, while the 12.8-liter MBE 4000, rated at 350 to 450 horsepower, is standard in most vehicles with medium-length hoods. Its Class 8 engine vendor is Caterpillar, which will supply 335- to 430-hp C13 and 435- to 625-hp C15 diesels for certain Freightliner models. The Condor heavy-duty, low-cabover is no longer offered, as it went with the American La France factory and product line that Freightliner sold earlier this year.

General Motors

GMC TopKick and Chevrolet Kodiak (shown) midrange conventionals and T-series tiltcabs become Class 8 models when built with heavy-duty axles, suspensions, brakes and other appropriate chassis parts. Later in '07, the C8500 will be available with a Meritor 18,000-pound-capacity front axle (2,000 pounds higher than the current heaviest steer axle), primarily for municipal business. A Dana 46,000-pound tandem (versus 45,000 now) on a Hendrickson Haulmaxx rubber suspension will also be a new option. Standard power for C8500s is the 7.8-liter Isuzu 6H (formerly called the Duramax 7800), rated at 215 to 300 horsepower, with aftertreatment and other changes for '07. Caterpillar's C7, at 207 to 300 horsepower, is a $1,000 option. The 325-hp, 8.1-liter Vortec 8100 V-8 is also available, making GM the only builder to offer gasoline power in Class 8. The '07-spec Isuzu 6H diesel is the only engine available in T8500s, which are otherwise unchanged.


International's 7700 (shown), powered by Cat or Cummins big-bore engines, gets a taller hood to house bigger radiators — probably the most visible change to any of the '07-model vocational trucks or highway trucks. The 5000i vocational vehicles now carry the PayStar name that had been dropped several years ago. It's part of the builder's return to once-popular Star-suffixed monikers for a number of models. Cat's C13 and C15 and Cummins ISM and ISX are the largest engines in Class 8 models; Cummins' ISL will be the lightweight engine in certain heavy applications, and its own DT and HT 570 and DT 466 will go in others. Later in '07, the MaxxForce heavy-duty diesels developed with MAN of Germany will debut.

Indiana Phoenix

Phoenix front-discharge concrete mixers are the specialty of this niche builder, which produces models with three to seven axles. It also offers water tank and "slinger" bodies on its front-cab, rear-engine chassis. Sometimes half of Indiana Phoenix's production is glider kits, which come as new frames, cabs, wiring, suspensions, tanks, fenders and mixer bodies with customers' powertrains and axles; a kitted mixer costs about half the price of a new truck. The company expects interest in gliders to grow as customers become more aware of higher prices for new trucks starting in January. Engines planned for '07 are Cummins' ISM and Cat's C13, mated to Allison RDX automatic transmissions.


VHD (shown) continues as Volvo's vocational truck, and will come only with a new D13 diesel, rated at 335 to 485 horsepower. The high-hood VT800 tractor can be ordered with the '07-spec Volvo D16, with 450 to 600 horsepower (but with "only" 2,050 pounds-feet, as the 2,250-lbs.-feet version is being dropped); also available in the VT are various ratings of the Cummins ISX. New mid-roof sleepers for VT/VN tractors might interest long-haulers of construction supplies using flatbed trailers; sleepers are 2 feet shorter to better match load heights, and weigh less than high-roof sleepers. The D13 and lighter-weight D11, with 325 to 405 horsepower, will replace the D12 starting in January. New D engines will be similar to Mack's MP series and will be built by Volvo Powertrain in Hagerstown, Md.

Terex Advance

Terex front-discharge, rear-engine mixers (formerly called Advance and Riteway) are offered with three to seven axles for use in states with varying weight laws. The builder also "glider kits" trucks using new cab and chassis components with customers' powertrains and axles. Cummins ISM and Cat C13 diesels are the '07 engines, and are mated to Allison RDX automatic transmissions. One-third of Terex Advance's new-truck production involves building and installing its own rear-discharge mixer drums on new conventional-cab chassis of various makes.


S-Series rear-engine, front-discharge mixer chassis (shown) is an integrated product using mixer bodies from McNeilus, an Oshkosh subsidiary, with steel drums or lightweight Revolution composite drums. S's can be ordered with a variety of axle configurations, and are built as new or glider-kitted trucks. Extensive experience in building military trucks went into the design of the Highland, Oshkosh's tall conventional-cab model using rear-discharge McNeilus mixers. Highland is available as a 6×6 or 6×4, the latter with an independent front suspension. Cat's C13 and Cummins' ISM are the chosen '07 diesels for both truck series.


In preparing for '07, Mack upgraded its conventional-cab vocational and highway vehicles, and all models, including the MR and LE low-cab-forward vocational trucks, will have only Mack diesels. The Granite (shown) gets a 4-inch-longer cab with new interior features, and a roomier and fancier Pinnacle replaces the Vision and CH highway models. Mack Power diesels, like those for sister company Volvo Trucks, were designed by Volvo Powertrain and will be built in Hagerstown, Md. First is an 11-liter MP7, which is now offered without '07 aftertreatment equipment in certain Granites; in January the MP7 gets aftertreated. Later in '07, a 13-liter MP8 will debut. The MP7 has ratings of 325 to 405 horsepower and the MP8 will go from 425 to 485. The MP engines will come in Maxidyne, MaxiCruise and Econodyne versions. Mack says MPs are more fuel efficient than current ASET engines (which will be gone by year's end), and have unique parts, controls and operating characteristics to differentiate them from Volvo Trucks' versions.


Extensive changes for '07 engines have caused Peterbilt to re-style most of its Class 8 models and give them new designations. The vocational 365 and 367 (shown) replace the current 357 and 378 truck. And Model 340 joins the 335 as Peterbilt's "heavy 7" offering. The traditionally styled long-nose 389 with smoother exterior styling replaces the current 379 (a common dump-truck model on the West Coast), and the medium-nose 388 replaces the 378 tractor. The aerodynamically styled medium-hood 384 and 387 day cab join the long-hood 386 to complete Peterbilt's aero truck lineup. Long-nose Class 8 vehicles will use the 15-liter Cummins ISX, from 385 to 565 horsepower, and Cat's C15, from 435 to 625 horsepower, while medium-nose will have the 11-liter Cummins ISM, from 280 to 450 horsepower, and Cat's C13, from 335 to 430 horsepower. Cummins ISL and Cat C9 diesels will continue as lightweight options. As with Kenworth, Peterbilt's medium- and medium-heavy models will use a new series of Cummins-built 6.7- and 8.3-liter diesels, called PX-6 and PX-8, respectively. Cat's C7 is being dropped.


All Sterlings get revised pedal designs and all pedals are suspended. A-Line cabs are standard with air-bag rear supports and air conditioning. The midrange and Baby 8 Acterra is now available with an extended cab, with rear seats or bunks and cargo access doors, and the four-door crew cab Acterra can be ordered with power windows and locks. As part of the Freightliner family, Sterling will use 14-liter Detroit Series 60 engines as standard in its A- and L-Line (shown) 9500 models. Depending on the BBC-configuration, the 12.8-liter MBE4000 and Caterpillar C13 and C15 diesel engines will be available as options. Power ratings will be the same as with Freightliner trucks. L- and Acterra models designated 8500 will be standard with 7.2-liter MBE 900 diesels rated from 190 to 330 horsepower; Cummins' 8.3-liter ISC with up to 315 horsepower will be optional.

Western Star

The 4900 series (shown) is often built for vocational duty, and the extra-heavy-duty 6900 is more at home off-road than on. As part of the Sterling organization, Western Star will use the Detroit Series 60 in its 4900 FA and SA models, with the MBE 4000 and Cat C13 and C15 engines as options. The 6900XD will have the Series 60 engine as standard and the Cat C15 as an option. 'Stars have enough room in the radiator area of their hoods to accommodate larger cooling packages for '07, so unlike some trucks, their frames didn't have to be modified to accept them.


Kenworth's T800 (shown) is optional with Big Power ratings — up to 625 horsepower — of Cat's C15, which were formerly limited to the W900. Bendix Spicer air disc brakes on steer and drive axles will be optional on certain truck and tractor models (they were offered on T2000 steer axles only). Extensive underhood changes for '07 engines include larger cooling packages, revised radiators for most models, and standard silicone hoses and extended-life coolant. KW's heavy diesel offerings include Cummins ISL, ISM and ISX, and Cat C9, C13 and C15. The medium-duty T330 will use a new series of Paccar-branded, Cummins-built 6.7- and 8.3-liter diesels, called PX-6 and PX-8. Cat's C7 is being dropped.

Click here to read Are You Ready for January '07 Engines?