Weichai WP10, WP12 and WP13 engines: displacement, ratings and versions

The Weichai WP10, WP12 and WP13 are six-cylinder engines for trucks and buses from Weichai Power. Weichai’s product pages give the WP10 as a 9.726-litre diesel with a mechanical injection pump, the WP10H as a 9.5-litre diesel of its H-series, the WP12 as an 11.596-litre diesel of its Blue Engine series and the WP12H as an 11.5-litre H-series diesel. Weichai’s Indian website lists a 12.54-litre WP13 diesel, and Weichai lists a natural-gas engine of the same displacement, the WP13NG, for city buses. The versions on these pages run from Euro II to Euro VI and from 220 kW to 405 kW. On this site the SHACMAN X3000 lists WP10, WP12 and WP13 engines.

Status as of 26 October 2026. Read that day: eight product pages on Weichai Power’s English website — the WP10 for tractors and for dump trucks, the WP10H for tractors and for tourist buses, the WP12 for special-purpose vehicles, the WP12H for tourist buses and for transit buses, and the WP13NG for transit buses — and the WP10H, WP12 and WP13 pages of Weichai’s Indian website. All eleven are the maker’s own documents.

Maker, codes and layout

Every specification block on Weichai Power’s English pages gives six cylinders in line, four valves and “Turbocharged and intercooled” air intake. Weichai’s Indian pages give four valves per cylinder and the cylinder count with bore and stroke: “6-116×150” mm for the WP10H, “6-126×155” for the WP12 and “6-127×165” for the WP13. The documents read do not explain the model codes; each row of Weichai’s model tables gives the emission standard and the technical route separately, as reproduced below.

Weichai describes the WP10 as an engine with a “large-displacement mechanical injection pump” and says that “The pure mechanical injection pump design eliminates the need for an ECU”. Its two WP10 pages name logistics and heavy-duty transport for the tractor version and muck and construction-material transport for the dump-truck version.

The WP10H and WP12H belong to what Weichai calls its H-series. The WP10H pages say that “Weichai H-series products offer three displacements on a single platform”, without naming the three. The WP10H tractor page lists a one-piece cylinder head with an integrated intake manifold and a “Proprietary ECU, fully independently developed”, and gives the engine “WCBS in-cylinder braking with a rated-speed braking power of 226 kW (23.8 kW/L)”; the Indian WP10H page gives “WCBS braking power up to 302.84 HP”. Engine brakes and retarders as endurance braking are covered in what is a retarder. Weichai calls the WP12H the latest product of its H-series platform, with a displacement of 11.5 L, and says its family-based modular design “offers high commonality of parts across 11–15L products”.

Weichai places the WP12 in its Blue Engine series and describes “a frame-type engine block and split cylinder head design”. Its page names hazardous chemical transport vehicles, truck-mounted cranes, concrete mixer trucks and concrete pump trucks among its uses.

For the WP13 diesel, Weichai’s Indian page gives “a 12.54L displacement”, a high-pressure common rail system, a “specially tuned turbocharger” and “DOC, DPF, and SCR after-treatment along with cooled EGR”. For the WP13NG gas engine, Weichai names an EGR module, a dual-channel design and anti-surge among its technologies, and a cast aluminium flywheel housing.

Versions and dates

None of the eleven documents read gives a date for any version, and none says when the WP10, WP12 or WP13 first appeared. The one dated document behind any figure on this page is SHACMAN’s X3000 export brochure of 2021, which the SHACMAN X3000 page cites for the engines in the last section of this page. The versions as Weichai’s pages present them on 26 October 2026:

Weichai’s Indian pages describe the equipment as a “High Pressure Common Rail System (HPCRS)”, “Diesel Oxidation Catalysts (DOC), Diesel Particulate Filters (DPF) and Selective Catalytic Reduction (SCR) catalysts”, and “Cooled Engine Exhaust Gas Re-circulation”. None of the documents read spells out the table abbreviations CR, Hi-SCR, ER or TWC. SCR and the AdBlue it uses are covered in SCR and AdBlue explained.

Fuels and emission standards

Weichai lists diesel as the fuel of the WP10, WP10H, WP12 and WP12H, and its Indian site calls the WP13 a diesel engine. The WP13NG is listed with “Natural gas” as its fuel, lean burn as the technical route of its Euro V versions and “ER+EGR+TWC” for its Euro VI versions; the page does not say whether the gas is carried compressed or liquefied. Gas engines in trucks and the liquefied form of the fuel are covered in LNG and bio-LNG trucks. None of the documents read mentions HVO or other renewable fuels for these engines.

Weichai’s tables give Euro II for the WP10, Euro III, Euro V and Euro VI for the WP10H, WP12 and WP12H, and Euro V and Euro VI for the WP13NG. The WP10 and WP12 rows with a mechanical injection pump that carry no Euro class are marked “/” in the emission column. Weichai’s Indian WP13 page names no class; it says the aftertreatment and cooled EGR help the engine “meet the latest emission norms”. The Indian WP12 page describes the engine as “engineered for Euro V compliance” while its table lists the WP12.400E62, WP12.430E62 and WP12.460E62, which Weichai Power’s English WP12 page lists as Euro VI for the two codes it shares. How the Euro steps for heavy engines are numbered is explained in Euro VI and Euro 7.

Ratings as Weichai lists them

Weichai’s model tables give each rating as rated power at an engine speed and peak torque over a speed band; the tables below give them in that form. The summary lines on its pages also print power in kW and Ps together, for example “220-280/300-380” kW/Ps for the WP10 and “294-338/400-460” for the WP13NG. How kilowatts, PS and newton-metres relate is explained in reading truck power figures.

WP10 (9.726 litres)

Both pages list the same five rows and name tractors, cargo trucks, special-purpose vehicles and dump trucks as target applications. Two codes appear twice, once as Euro II and once without a class, with different torque.

WP10H (9.5 litres)

The tractor page names tractors, cargo trucks, dump trucks and special-purpose vehicles as target applications, the tourist-bus page city buses and tourist buses. Weichai’s Indian WP10H page lists the WP10H375E62 and WP10H400E62 with the same power and torque and the technical route “CR+DOC+DPF+HiSCR”.

WP12 (11.596 litres)

The special-purpose-vehicle page names tractors, dump trucks, cargo trucks and special-purpose vehicles as target applications for every row. Weichai’s Indian WP12 page lists the WP12.430E62 and WP12.460E62 with the same power and torque and the technical route “CR+DOC+DPF+Hi-SCR”.

WP12H (11.5 litres)

The summary line of both pages gives the torque as “2000/950-1400” N·m at r/min, while the model table gives 900–1,300 or 900–1,400 rpm. The transit-bus page’s summary names city buses as the target application; the rows of its model table read “Target applications: tourist bus”, as on the tourist-bus page.

WP13 (12.54 litres, diesel)

The Indian page describes the WP13 series as built for heavy on-road trucks. No WP13 diesel page on Weichai Power’s English website was among the documents read.

WP13NG (12.54 litres, natural gas)

The page’s overview says “Power output ranges from 294 to 353 kW”; its specification block gives “294-338” kW and its model table has no rating above 338 kW. Its list of features gives a torque of 2300 N·m and “specific torque reaching 183 N·m/L”.

Trucks and buses on this site with the Weichai WP10, WP12 and WP13

One model on this site records these engines in kilowatts and newton-metres: the SHACMAN X3000, with three entries taken from SHACMAN’s X3000 export brochure of 2021, the only SHACMAN document opened for that page that gives kilowatt figures for X3000 engines. The figures below are those of the model’s own page and the source it cites, as that page records each engine; they are not the engine-level tables above. The WP13.550E501 code does not appear in the Weichai documents read for this page.

The SHACMAN X6000 page also names Weichai WP13 engines, the WP13.480E501 for the 4x2 tractor and the WP13.550E501 for the 6x4, but is not in the table, because no SHACMAN document opened for that page gives a kilowatt figure for an X6000 engine.