HOWO 371 Truck Models Explained: Specifications and Differences
HOWO 371 appears in listings for several different trucks. Some are tractor heads, some are three-axle dump trucks, and others are four-axle tippers, cargo trucks or concrete mixers.
The number 371 refers to the engine’s power designation. To identify the truck itself, you need the complete model code, its axle layout and the equipment fitted behind the cab.
Codes such as ZZ4257S3241W, ZZ3257N3847A and ZZ3317N3567W describe different vehicles, even though all may be advertised as HOWO 371.
This article focuses on classic configurations using the WD615.47 engine. The figures come from SINOTRUK manuals and published manufacturer, supplier or distributor specification sheets. Each table describes a particular configuration, often an earlier export version. Trucks carrying the same model name can differ by production period, market and order specification.
The WD615.47 engine provides the starting point. It is a 9.726-litre, inline six-cylinder diesel with water cooling, turbocharging and intercooling.
For the Euro II version covered by the SINOTRUK manual cited below, the specifications are:
Item
WD615.47 specification
Fuel
Diesel
Cylinder arrangement
Inline six-cylinder
Operating cycle
Four-stroke
Displacement
9.726 L
Bore × stroke
126 × 130 mm
Air intake
Turbocharged and intercooled
Cooling
Water-cooled
Rated power
273 kW, approximately 371 PS
Rated engine speed
2,200 rpm
Maximum torque
1,500 N·m
Maximum torque speed range
1,100–1,600 rpm
Emission version
Euro II
The power figure above uses metric horsepower, expressed as PS. Vehicle listings often advertise the truck simply as “371 HP.” Some sales sheets also give different torque figures or speed ranges, so the complete engine designation and its identification plate should be checked when assessing an individual truck. The table follows the figures in the SINOTRUK HOWO-A7 driver’s manual.
Displacement, power and torque describe different aspects of the engine. Displacement is its working volume. Power affects the engine’s ability to sustain work at a given rate, while torque describes its turning force.
The torque speed range also matters. In this version, maximum torque is available between 1,100 and 1,600 rpm. The gearbox allows the driver to use that output across different vehicle speeds and loads.
That is one reason two trucks with the same 371 designation can behave differently: their transmissions, axle ratios, tyres and operating weights may be different.
The 4×2 and 6×4 tractor heads illustrate this clearly. Both connect to a semi-trailer through a fifth wheel, but their axle arrangements and chassis specifications differ.
The comparison below uses the ZZ4187N3617 published by Hubei Huawin and a supplier-listed ZZ4257S3241W configuration.
Item
HOWO 371 4×2 tractor
HOWO 371 6×4 tractor
Listed model
ZZ4187N3617
ZZ4257S3241W
Drive configuration
4×2
6×4
Number of axles
2
3
Driven axles
1
2
Engine
WD615.47
WD615.47
Advertised power
371
371
Transmission
HW19710, 10 forward and 2 reverse gears
HW19710, 10-speed manual
Cab
HW76, single sleeper, air conditioning
HW76 flat-roof, single sleeper, air conditioning
Overall dimensions, L × W × H
6,100 × 2,500 × 3,150 mm
6,800 × 2,496 × 2,958 mm
Wheelbase
3,500 mm
3,200 + 1,400 mm
Published kerb weight
7,180 kg
8,800 kg
Front axle
Published rating: 7,000 kg
HF7, published rating: 7,000 kg
Rear axle arrangement
Single drive axle, published rating: 16,000 kg
ST16 double-reduction drive axles
Fuel tank
400 L
400 L
Tyres
12R22.5, 6 fitted + 1 spare
12R22.5, 10 fitted + 1 spare
Clutch diameter
430 mm
430 mm
Published maximum speed
102 km/h
102 km/h
These figures refer to the specific builds in the Hubei Huawin 4×2 specification and the supplier’s ZZ4257S3241W specification.
In this comparison, the 4×2 is shorter and lighter. With one fewer axle, it also has fewer tyres and fewer axle-related components. Where the transport task allows it, that layout can help keep tractor weight down.
The 6×4 has two driven axles. This changes how traction is distributed and can be relevant to loaded starts, gradients and surfaces with limited grip. Whether it is the more suitable configuration depends on the trailer, route and operating conditions.
The 6×4 wheelbase is written as 3,200 + 1,400 mm because the truck has two axle intervals. The first number is the distance from the front axle to the first rear axle; the second is the distance between the rear axles.
Weight terminology needs equal attention. The supplier’s 6×4 sheet lists a total mass of 25,000 kg. This relates to the tractor and the load imposed through its fifth wheel. It does not mean that the tractor can carry 25 tonnes of cargo.
The payload of the complete combination depends on the trailer, its own weight, the vehicle documents and the conditions under which the combination is permitted to operate.
For a 6×4 dump truck, ZZ3257N3847A is a useful model to examine. Published versions differ. The following table uses a Philippine distributor’s A7 low-roof configuration with the 371 engine.
Item
Listed ZZ3257N3847A configuration
Vehicle type
Dump truck
Drive configuration
6×4
Cab
A7-W low-roof, single sleeper
Engine
WD615.47-20
Advertised power
371
Maximum torque
1,500 N·m
Transmission
HW19710
Clutch diameter
430 mm
Front axle
HF9
Rear axles
HC16
Suspension
Multi-leaf springs
Fuel tank
300 L
Tyres
12.00R20
Dump body dimensions
5,600 × 2,300 × 1,500 mm
Floor thickness
8 mm
Side plate thickness
6 mm
Listed body steel
T700 high-strength steel
Distributor-listed gross vehicle weight
33,000 kg
Distributor-listed payload
20,000 kg
The mass figures are the distributor’s published values for this overseas configuration. They should be checked against the documents for the vehicle and market concerned. The figures come from the A7 dump truck specification sheet.
This truck has three axles, with both rear axles driven. Its chassis and body must accommodate repeated loading, travel over working surfaces and hydraulic tipping.
The body dimensions deserve a closer look. Converted to metres, they are 5.6 × 2.3 × 1.5. If these are internal dimensions and the body is treated as a rectangular box, the calculated volume is approximately 19.32 m³.
The distributor places the body in the approximately 20 m³ class. For a technical article or purchasing specification, retaining the dimensions makes the capacity claim easier to understand.
Volume alone does not establish payload. The same body filled with different materials can contain very different weights. Material density, the vehicle’s available payload and axle loading all have to be considered.
The 8 mm floor and 6 mm sides describe this particular body construction. Resistance to damage also depends on steel grade, reinforcement, welding and loading practice. Large rocks dropped into the body create a different impact load from fine material placed gradually.
The A7-W cab in this table must also be distinguished from HOWO dump trucks fitted with an HW76 cab. The 371 designation does not fix the cab, body dimensions or overall height.
The ZZ3317N3567W represents a four-axle, 8×4 dump truck configuration. The following figures are taken from CANMAX’s published 371 specification.
Item
Listed ZZ3317N3567W configuration
Drive configuration
8×4
Number of axles
4
Engine
WD615.47
Power
273 kW, approximately 371 PS
Rated engine speed
2,200 rpm
Maximum torque
1,500 N·m
Maximum torque speed range
1,100–1,600 rpm
Emission version
Euro II
Transmission
HW19710, 10 forward and 2 reverse gears
Overall dimensions
10,150 × 2,550 × 3,500 mm
Wheelbase
1,800 + 3,500 + 1,350 mm
Front axles
Two HF9 axles, each listed at 9,000 kg
Rear axles
Two HC16 axles, each listed at 16,000 kg
Tyre options
12.00-20 or 12.00R20
Tyre quantity
12 fitted + 1 spare
Dump body dimensions
7,300 × 2,300 × 1,500 mm
Tipping arrangement
Front-mounted lifting cylinder
Floor thickness options
8, 10 or 12 mm
Side plate thickness options
4, 6 or 8 mm
Published maximum speed
75 km/h
The plate thicknesses are alternatives offered on the supplier’s page. They are not a single fixed specification. See the CANMAX HOWO 371 8×4 configuration.
The three wheelbase figures describe the three intervals between the four axles: first to second, second to third, and third to fourth.
Compared with the 5.6-metre body on the earlier 6×4 example, this truck uses a 7.3-metre body. Treating the listed dimensions as a rectangular space gives a calculated volume of approximately 25.2 m³. Actual usable capacity depends on the internal dimensions and body shape.
The longer truck also needs more space when entering a loading area, turning or reversing. The extra axle changes load distribution, but it does not establish a universal payload figure.
Two rear axles each described as “16 tonne” do not automatically give the truck a 32-tonne cargo allowance. Axle ratings are component figures. The weight of the truck itself, the other chassis components and the vehicle’s permitted operating limits must also be accounted for.
A HOWO 371 cargo truck uses a fixed body rather than a tipping body. Body length, chassis wheelbase and body construction become central parts of its specification.
One supplier lists the following ZZ1257N4647B1 build:
Item
Listed ZZ1257N4647B1 configuration
Drive configuration
6×4
Engine
WD615.47
Displacement
9.726 L
Advertised power
371
Transmission
HW19710, 10 forward and 2 reverse gears
Cab
HW76, single sleeper, air conditioning
Front axle
VGD95, listed at 9,500 kg
Rear axles
MCX16ZG, listed at 2 × 16,000 kg
Steering
ZF8118 hydraulic power steering
Tyres
12.00R20, with spare tyre
Fuel tank
400 L
Cargo body
Built to order
This specification uses a different axle combination from the HF9 and HC16 arrangement in the dump truck example. It demonstrates why the engine’s power designation is insufficient to identify the chassis equipment. The figures are from the supplier’s ZZ1257N4647B1 listing.
Cargo body dimensions should be recorded separately from chassis specifications. Different body lengths, side heights and body weights can change load distribution, kerb weight and manoeuvrability.
A bulky, low-density load may use the available body volume before reaching the weight limit. A dense load may reach the weight limit while leaving much of the body empty. Raising the sides increases volume; it does not establish a higher permitted payload.
Concrete mixers add another set of components to check. Alongside the driving chassis, there is a hydraulic system and a reduction unit for the drum.
The following A7 6×4 mixer configuration is published by a Philippine distributor. Its catalogue lists ZZ1257N3847N1, a chassis-related designation that should be checked separately from the completed mixer vehicle’s full model code.
Item
Listed A7 6×4, 371 mixer configuration
Catalogue-listed designation
ZZ1257N3847N1
Drive configuration
6×4
Cab
A7-W low-roof, single sleeper
Engine
WD615.47-20
Advertised power
371
Maximum torque
1,500 N·m
Transmission
HW19710
Clutch diameter
430 mm
Front axle
HF9
Rear axles
HC16
Suspension
Multi-leaf springs
Fuel tank
300 L
Tyres
12.00R20
Published mixer capacity
10 m³
Hydraulic pump
EATON 5423-518
Hydraulic motor
EATON 5433-216
Drum reduction unit
TOPUNION P68
Distributor-listed gross vehicle weight
33,000 kg
Distributor-listed payload
20,000 kg
These are the components and mass figures published for that overseas configuration in the A7 mixer specification sheet.
The HW19710 transmission controls the truck’s driving gears. The drum reduction unit serves a different purpose: it forms part of the equipment that turns the mixer drum.
The hydraulic pump, hydraulic motor and drum reduction unit should therefore be identified individually. Their model numbers matter when assessing equipment compatibility or ordering replacement parts.
A second published 371 mixer configuration from Hubei Huawin shows how dimensions and equipment can change:
Item
Separate Hubei Huawin 371 mixer configuration
Overall dimensions
9,300 × 2,500 × 3,950 mm
Wheelbase
3,825 + 1,350 mm
Published kerb weight
13,500 kg
Engine
WD615.47, advertised as 371
Transmission
HW19710, 10 forward and 2 reverse gears
Fuel tank
400 L
Tyres
12R22.5
Published drum capacity
10 m³
Drum shell thickness
5 mm
End plate thickness
6 mm
These figures belong to the separate Hubei Huawin configuration. Its dimensions, wheelbase and 400-litre tank should not be inserted into the preceding A7 table.
A “10 m³” description also needs context. Confirm whether it refers to geometric drum volume or rated mixing capacity. The amount of concrete carried must then be considered alongside material density, available payload and axle loading.
The HW19710 gearbox appears across several of these trucks. Selected parameters in SINOTRUK’s manual include:
Item
HW19710 manual specification
Input torque rating
1,900 N·m
Forward gears
10
First gear ratio
14.28
Second gear ratio
10.62
Third gear ratio
7.87
Fourth gear ratio
5.88
The same manual lists variants including HW19710C and HW19710T with differences in torque ratings or ratios. The complete suffix should be retained when checking the transmission. These figures are drawn from the SINOTRUK transmission parameter table.
A high numerical ratio in a low gear multiplies engine torque to help the truck start moving. Higher driving gears progressively reduce that multiplication as vehicle speed increases.
The drive axle ratio adds another stage of reduction. As a simple comparison, a ratio of 5.73 provides approximately 30% more theoretical torque multiplication than 4.42, with other transmission conditions held equal. It also changes the rotational speed required at a given road speed.
This is why the engine, gearbox and axle ratio need to be considered together. A 371-powered tractor intended for road transport can have different requirements from a 371-powered tipper making repeated loaded starts on working surfaces.
When recording an individual HOWO 371, start with its complete model code and production details. Then note the engine, transmission suffix, axle models and ratios, wheelbase, body dimensions and vehicle mass figures.
A ZZ4257S3241W tractor works with a semi-trailer. A ZZ3257N3847A dump truck has to accommodate hydraulic tipping. A concrete mixer has an additional drum-drive system to maintain. Those details establish what the truck is equipped to do, well beyond the 371 badge.