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  1939-1940年,美國陸軍軍械部隊招標噸戰術6×6越野車。斯蒂龐克、通用汽車下屬的黃色客車製造公司、萬國收割機公司提交了設計並於1941年投產。  US-6 噸戰術6×6越野車與相關的5噸6x4卡車,總計生產了13個車型219,882輛。其中197,678輛在印第安納州南本德工廠生產。 REO公司在芝加哥工廠從1944年生產了22,204輛US6 U9卡車(無前絞盤)。1945年停產。

  大部分車輛根據租借法案援助蘇聯,因為其競爭對手GMC 6x6 CCKW被認為更適合於西線戰場。1941年秋,第一輛US6卡車運抵蘇聯。1942年7月蘇聯紅軍測試了11臺6x6“斯蒂龐克”(這是蘇聯對此型車的稱呼),結果把車的載重從2.5噸擴大為4噸。1945年,車載重降低為噸,在良好路面可載重5噸。  大量US6通過波斯走廊運入蘇聯。  US6卡車也被美軍用於開闢中印公路與阿拉斯加公路。  二戰後,US6強烈影響了蘇聯ZiS-151卡車與ZiL-157越野車的設計。

  

  The US6 used a Hercules JXD engine, with an L-head inline 6 cylinder gasoline engine developing at 2800 rpm and of torque at 1150 rpm. A conservative-type and highly-reliable engine with a compression ratio of only 5.82:1, it could use 72-octane gasoline. This same engine was also used in the M3 half-tracks and, later, M8 Greyhound and M20 armoured cars (the latter was a variant (lacking the gun turret) of the M8 Greyhound).  The Warner T 93 5 speed transmission had a very low first, a direct fourth and an overdrive fifth gear. A power take-off could be fitted to operate a winch (mounted just below in front of the radiator) and/or the hydraulic hoist on dump trucks (the U10/U11 and U12/U13 dump truck models).  The Timken T-79 transfer case had high and low ranges, a neutral position and could either engage or disengage the front axle. There was one output shaft mounted forward to the front axle (not used in 6x4 trucks) and two to the rear, with one for each rear axle.  Both front and rear axles were of the Timken split-type with a ratio of 6.6:1. The front axle had ball-type constant-velocity joints while the two at the rear were full-floating.

  The US6 had a ladder frame with three beam axles, the front on semi elliptical leaf springs, the rear tandem on quarter elliptical leaf springs with locating arms.  There were two wheelbases, the short, used in semi tractors, dump trucks, and short cargo models, and the long, used in tankers, long cargo models, and the U9 chassis cab (measurements are from the centerline of the front axle to the centerline of rear bogie). All models had 7.50-20” tires and dual rear tires. 6x4 models, intended for on road use only, were rated at 5 tons (4536 kg), twice the 6x6’s off-road rating.

  The US6 carried the design of Studebaker’s civilian truck cab, although it was modified for military use. Studebaker trucks were different from other 6x6 trucks built for the war effort of the USA because vent windows were included in each door. These vent windows were separate from the main window that rolled down into the door-frame and could be swung out to help with the truck cab's ventilation.  Studebaker also designed the open-type military truck cab which was featured on the GMC CCKW (later models), but their major customer, the USSR, preferred the closed cab for their generally harsh (cold-weather) climate. While Studebaker's open-type truck cab became the American standard, production of the US6 with the closed-type truck cab was restarted after only 10,000 units of the former.

  U1與U2載重卡車(裝有前絞盤)是短軸距,備胎在駕駛室下,車廂長僅。主要用於運輸。  U3/U4與6x4 U7/U8載重卡車是長軸距,備胎在長的貨箱下面。總計生產了197,000臺貨箱車型。  U5油車是長軸距,兩個獨立的載油箱,無絞車。  6x4 U6半掛牽引車,無絞車。  U9載重卡車是長軸距,無絞車。蘇聯的喀秋莎火箭炮的載車。  U10/U11 (尾側) 與U12/U13 (邊側)自卸卡車是短軸距。
斯蒂龐克US6(G630)是美國二戰時期一個21⁄2噸6x6越野車與5噸6x4卡車系列,由斯蒂龐克公司與REO汽車公司製造。