126.96.36.199 Maximum geared speed. Maximum geared speed at engine governed speed shall
be not less than 58 mph for 4x2 and 6x4 models and not less than 52 mph for 4x4 and 6x6
models. Conformance to geared speed specified shall be determined by calculating in
accordance with the following formula:
Maximum geared speed (mph) =
Governed speed (rpm)
Total gear reduction x tire factor (see 6.3)
3.3.2 Service brakes. The service brakes shall control and hold the vehicle, when loaded
to its specified GVW, on a 30 percent grade. The service brakes shall stop the vehicle, loaded to
specified GVW, within the stopping distance requirements of Federal Motor Carrier Safety
3.4 Chassis components.
3.4.1 Engine. The engine furnished shall be the chassis manufacturer's standard or
optional engine for the commercial model truck which meets or exceeds the requirements of this
188.8.131.52 Diesel engine. Unless otherwise specified (see 184.108.40.206), the vehicle shall be
equipped with a liquid cooled, compression ignition, two-stroke or four-stroke cycle diesel
engine. The engine net horsepower figures used in performance prediction calculations shall be
determined in accordance with SAE J1349. The engine shall demonstrate the performance
characteristics specified herein when using diesel fuel conforming to VV-F-800. In addition,
when specified (see 6.2), the engine shall operate satisfactorily on grade JP-4 and grade JP-5 fuel
conforming to MIL-T-5624 under emergency, short duration conditions and on grade JP-8 fuel
conforming to MIL-T-83133 under normal conditions. A power loss when operating on JP-4,
JP-5 or JP-8 is acceptable.
220.127.116.11 Gasoline engine. When specified (see 6.2), class 16, 19, and 28 vehicles shall be
equipped with a liquid cooled, internal combustion, four-stroke cycle gasoline engine with not
less than six cylinders. The engine shall produce the required vehicle performance when
operated on unleaded fuel with a research octane rating of 91, at an engine speed not more than
the manufacturer's recommended operating speed. The engine shall be capable of warranted
operation on unleaded fuel, when used in accordance with the operator's manual. Engine net
horsepower used in performance prediction calculations shall be determined in accordance with
18.104.22.168 Oil filter. A full flow type oil filter shall be furnished.
22.214.171.124 Governor. An engine governor shall be furnished and set and sealed to limit the
engine speed to the engine manufacturer's recommended operating speed.