The Qingling Isuzu 4KH1 engine is the core model in Isuzu’s 4K series. As an upgraded conventional diesel engine, it builds upon and further refines the classic 4JB1 technology. Launched in the early 21st century, it has become the primary powertrain for Qingling light trucks, pickup trucks, and medium‑size commercial vehicles thanks to its superior power output, enhanced fuel efficiency, and broader compatibility. Dubbed the “power benchmark” in the commercial vehicle sector, it is widely used in various commercial vehicles and construction machinery, balancing practicality with high efficiency. After years of market validation, it has emerged as a trusted, classic conventional diesel engine within the industry.
I. Core Basic Parameters
The 4KH1 conventional internal combustion engine uses diesel as its fuel and employs a traditional fuel supply system. It incorporates Isuzu’s advanced manufacturing processes, with core parameters optimized through multiple iterations to strike a balance between power and fuel efficiency, as follows:
Project
4KH1-TCG40 (China IV / Euro IV)
4KH1-TCG50 (China V / Euro V)
4KH1-TCG60 (China VI / Euro VI)
General Notes on Foreign Trade
Brand and Model
Qingling Isuzu 4KH1
Qingling Isuzu 4KH1
Qingling Isuzu 4KH1
Inline four-cylinder, liquid-cooled, turbocharged with intercooler, high‑pressure common rail
Bore × Stroke
φ95.4×104.9mm
φ95.4×104.9mm
φ95.4×104.9mm
Displacement: 2.999L (3.0L class)
Compression ratio
17.5:1
17.5:1
17.5:1
Efficient combustion, low fuel consumption, high power.
Rated power
88 kW (120 hp) at 2,900 rpm
96 kW (130 hp) at 2,900 rpm
105 kW (143 hp) at 2,900 rpm
Power coverage for light and medium loads, suitable for global operating conditions.
Maximum torque
290 N·m at 1500–2900 rpm
290 N·m at 1500–2900 rpm
320 N·m at 1500–2800 rpm
1500 rpm for maximum torque output , Strong in Heavy-Load Startups / Hill Climbing
Fuel System
Denso 1800 bar high-pressure common rail
Denso 1800 bar high-pressure common rail
Denso 1800 bar high-pressure common rail
Multi-stage injection boosts combustion efficiency by 8%.
Intake Method
Turbocharging + Intercooler
Turbocharging + Intercooler
VGS Variable-Geometry Turbo + Intercooler
Fast low-speed response, ample high-speed power.
Emission standards
China IV / Euro IV (DOC)
China V / Euro V (DOC+DPF)
China VI / Euro VI (DOC + DPF + SCR)
No urea required (for China V and below), simple maintenance.
Minimum fuel consumption
≤200 g/kW·h
≤195 g/kW·h
≤190 g/kW·h
Fuel consumption per 100 kilometers for light trucks 10–12 L Long-distance travel is more cost‑effective.
Idle Speed / Maximum RPM
700±25 rpm / 4000±50 rpm
700±25 rpm / 4000±50 rpm
700±25 rpm / 4000±50 rpm
Stable idling, suitable for long periods of idle operation.
External dimensions
784×725×605mm
784×725×605mm
784×725×605mm
Compact layout, compatible with 700P/600P cabs.
Dry weight
Approximately 290 kg
Approximately 295 kg
Approximately 300 kg
Lightweight design to enhance the vehicle’s payload capacity.
Compatible Vehicle Models
600P/700P light trucks and van cargo vehicles
700P medium-duty trucks, refrigerated transport, and construction vehicles
Left‑hand / right‑hand drive universal, with global after-sales coverage.
Engine Model The base model is the 4KH1 (naturally aspirated), while the upgraded models are the 4KH1-T/4KH1CT6H1 (turbocharged). Derivative models include the 4KH1CN5HS and others, all manufactured by Isuzu Qingling at the original factory, inheriting Isuzu’s authentic technology and compatible with Bosch and Denso high‑pressure common rail injection systems.
Cylinder Structure Inline four-cylinder, water-cooled, four-stroke, double overhead camshaft (DOHC) design with 4 valves per cylinder; the cylinder block is made of cast iron, while the cylinder head is crafted from aluminum alloy—offering high rigidity, excellent high‑temperature resistance, and lightweight construction. The crankshaft is precision forged and undergoes rigorous strengthening treatment, and the connecting rods are highly robust, effectively extending service life.
Displacement Specifications Standard displacement: 2.999 L (approximately 3.0 L), with bore × stroke dimensions optimized to meet the power output requirements of a 3.0 L engine. The compression ratio has been finely tuned for optimal performance, resulting in a compact design with ample power reserves, making it suitable for a wide range of medium‑size commercial vehicles and construction machinery applications.
Intake Method Available in both naturally aspirated (4KH1) and turbocharged (4KH1-T/4KH1CT6H1) versions, the turbocharged model is equipped with a Honeywell turbocharger and a Honeywell intercooler assembly, which can significantly boost power output and make it suitable for a variety of load scenarios.
Emission levels The main model complies with China VI emission standards, while certain derivative versions can be adapted to meet China V and non-road-related standards. Customized adjustments can be made in accordance with the laws and regulations of export regions, making it suitable for use in multiple regions worldwide. Some models do not require a urea system, thereby reducing operating costs.
II. Power Performance
As an upgraded conventional internal combustion engine, the 4KH1 engine builds on its proven advantages of stability and reliability while focusing on enhancing power output and fuel efficiency. It is ideally suited for heavy-load commercial vehicle applications, high‑efficiency transportation, and construction machinery operations. The specific performance parameters are as follows:
Naturally Aspirated Version (4KH1) The rated power can reach 96 kW (131 hp) at 3,400 rpm; the maximum torque is well-suited to medium- and light-load applications, delivering smooth and stable power output with quiet, steady idling—making it ideal for urban delivery, short-distance shuttle services within industrial parks, and other light-to-moderate load scenarios.
Turbocharged version (4KH1-T/4KH1CT6H1) The rated power ranges from 96 kW to 105 kW (131–143 hp), with some optimized versions delivering up to 150 hp at around 3,400 rpm. The maximum torque is 320–375 N·m, with a torque-speed range of 1,600–2,800 rpm. The engine responds swiftly in the low-speed range, delivering a noticeable boost in power and effectively meeting the demands of medium- to heavy-duty loads, uphill driving, and high-altitude operations, while minimizing power degradation.
Fuel economy It delivers outstanding low‑load fuel consumption, with some models achieving a fuel economy as low as 8.4 L per 100 km. The vehicle exhibits strong fuel compatibility, supporting both No. 0 diesel and low‑temperature diesel. Its conventional fuel supply system is mature and reliable, and when paired with an advanced electronically controlled fuel system, it can effectively manage long‑term operating costs.
Startup Performance It uses an electric start system, with a cold-start temperature as low as -25°C, making it suitable for various climatic conditions. The engine responds quickly upon startup, runs smoothly at idle, and delivers excellent noise control. After NVH optimization tailored to the vehicle model, the cab’s noise isolation performance is further enhanced.
III. Structural Features and Core Advantages
The reason why 4KH1 traditional internal combustion engines have become the main power source for commercial vehicles lies in their ability to build upon Isuzu’s legacy of reliability while optimizing structural design and enhancing power performance, thereby addressing the core pain points of commercial vehicle users—namely, “efficiency, reliability, and cost savings.” The specific advantages are as follows:
Extremely durable The combination of a cast-iron cylinder block with an aluminum alloy cylinder head strikes a balance between rigidity and lightweight design. The components are sourced from internationally renowned brands (such as Mahle pistons), resulting in a B10 life of up to 500,000 kilometers. Under typical operating conditions, the major overhaul interval generally exceeds 300,000 kilometers, with an extremely low failure rate that helps reduce downtime and maintenance costs.
Easy to maintain and low cost The structural design is simple; while retaining the advantages of traditional fuel-powered models, the layout of the electronic control system has been optimized. The components are highly versatile, easy to procure and easy to maintain, and the daily maintenance procedures are straightforward. Some models do not require a urea system, which helps reduce urea costs and maintenance time. Compared with new engines in the same class, the maintenance costs are more competitive.
Wide compatibility With its compact size and standardized mounting interfaces, it can be installed not only on light-duty trucks such as the Qingling KV600 and M600, but also on pickup trucks like the Daka H and T17, as well as small concrete mixers, mobile air compressors, and other construction machinery. It is suitable for a wide range of applications, including urban delivery, intercity logistics, and field operations.
Technologically mature and reliable. Based on Isuzu’s mature technology platform, which has been optimized and upgraded and has undergone years of market validation, the technical system is well-established with no obvious design flaws. It has low requirements for fuel quality and can adapt to complex operating conditions—whether in high-altitude areas, mountainous regions, or environments characterized by high temperatures and high humidity—delivering stable power output and responsive performance.
IV. Technology Inheritance and Application Scenarios
The 4KH1 engine was developed by Isuzu of Japan and represents Isuzu’s latest upgrade in the traditional internal combustion engine sector. As Isuzu’s closest partner in China, Qingling has localized and optimized the engine after introducing it to the Chinese market, launching multiple derivative models tailored for both domestic applications and export markets. Qingling consistently adheres to the authentic Isuzu technology, ensuring stable and reliable engine performance.
As a classic, traditional internal combustion engine, it has a wide range of applications, with its core use cases including:
Commercial Vehicle Sector: Light-duty trucks such as the Qingling KV600 and M600, and pickup trucks like the Daka H and T17, are designed for urban delivery, intercity logistics, and rural-urban logistics applications. They deliver robust power while maintaining fuel efficiency, thereby enhancing transportation efficiency.
Construction machinery field: Small concrete mixer trucks, mobile air compressors, combine harvesters, and other equipment that feature dual-drive systems for both locomotion and operation, adapting to complex construction environments with stable and efficient performance.
Auxiliary Power Applications: Auxiliary power generation for nearshore fishing vessels, silent power stations at temporary construction sites, and more—capable of achieving stable, long‑term operation at low speeds to meet a wide range of auxiliary power needs.
V. Summary
The Qingling Isuzu 4KH1 traditional fuel engine is an upgraded classic model centered on “high efficiency, reliability, and cost-effectiveness.” It inherits the reliable DNA of Isuzu’s 4-series engines, optimizing power output and fuel economy based on the 4JB1 platform while eliminating redundant technological features and focusing on addressing the core needs of commercial vehicle users: “efficient transportation, cost reduction, and fewer breakdowns.” After years of market experience, thanks to its mature technology, wide range of applications, and low maintenance costs, it has not only become the preferred powertrain for various commercial vehicles and construction machinery in China, but can also be custom‑configured to meet export requirements, adapting to the operational needs of regions such as Southeast Asia, the Middle East, and Africa—and thus continuing the legendary reputation of Isuzu engines.
Keywords:
4KH1 Traditional Internal Combustion Engine
