Doosan has introduced its first Tier 4-compliant wheel loaders—the DL300-5, DL350-5, DL420-5, DL450-5 and DL550-5—with a net horsepower range of 271 horsepower in the DL300-5 to 379 horsepower in the DL550-5.
The models replace the previous Tier 4-Interim models and are powered by Scania diesel engines. Doosan says the engines are optimized for use with a high-pressure common-rail fuel delivery system and a cooled EGR system. They utilize a DOC to reduce particulate matter and SCR and DEF aftertreatment to reduce nitrogen oxides—the same technology used to achieve Tier 4-Interim compliance in the size class.
Doosan added a mass airflow sensor and exhaust brake to its existing diesel technologies to help meet Tier 4-F emission standards. The mass airflow sensor allows the electronic control unit to improve the management of airflow from the variable geometry turbocharger (VGT), and to optimize fuel delivery to the combustion chamber based on engine air intake volume and rpm. The VGT enhances boost pressure throughout a wide rpm range of the engine, resulting in improved fuel efficiency at lower rpm, the company says. This also generates higher torque levels and faster engine response even at low rpm.
The exhaust brake helps to maintain consistent engine temperatures at lower engine speeds to improve operating efficiency. Consistent engine temperatures reduce harmful emission levels in the exhaust when the engine is running at lower rpm. Under normal operation, with high rpm, the exhaust brake is inactive.
The five wheel loaders feature cab enhancements including an improved adjustable steering column to provide more leg room and more floor space. Also inside the cab, a new fuel consumption gauge informs operators how much fuel the machine is using in real time. Updates to the keypad on the dashboard make it easier for operators to review, adjust settings, and to clean and maintain the keypad.
The loaders also have an auto-shutdown system to help reduce fuel consumption when the machine is sitting idle. Operators can configure the idle time from 3 to 60 minutes. When enabled, the feature will shut down the wheel loader’s engine when the preset idle time is met.
Rear LED lamps provide better visibility, especially when working on a job site at night. Limited slip differentials are also included and allow the machines to have more traction when working.
Updates to improve serviceability include a new air cleaner with longer replacement intervals. Additional oil sampling ports improve predictive maintenance procedures and various fluid pressures are now viewable via the dash panel, allowing monitoring from the cab.
Available as a factory-installed option, an auto-greasing system replaces daily greasing and helps to extend bearing bushing life. The optional auto-greasing system will grease the correct amount and when it’s needed to avoid over-greasing and under-greasing, which represents a considerable time savings for fleet owners and rental companies.
For applications in mining and infrastructure market segments, Doosan offers a high-lift configuration for all five new wheel loaders, providing additional dump height. Options for the DL300-5 through DL450-5 wheel loaders include hydraulic locking front and conventional rear differential; axle oil cooler for the DL420-5 and larger; emergency steer; 5-gear with lock-up clutch; hydraulic load isolation system; fingertip 3-lever controls; electric joystick steering; and a rearview camera.
The DL550-5 includes all the same options as the DL300-5 through DL450-5, except for the hydraulic locking front and conventional rear differential, which are standard equipment.
The DL300-5 through DL550-5 wheel loaders feature three selectable work modes, Economy, Standard, and Power, to better balance fuel consumption and machine power to the working conditions, Doosan says.
Wheel loaders come with a standard 3-year subscription to Doosan Telematics.
Dash 5 Wheel Loader Specifications
- Power: 270 horsepower
- Operating weight: 41,844 pounds
- Bucket capacity: 4.2 cubic yards
- Dump height: 9 feet 4 inches
- Breakout force: 37,768 pounds
- Power: 271 horsepower
- Operating weight: 43,541 pounds
- Bucket capacity: 4.8 cubic yards
- Dump height: 9 feet 7 inches
- Breakout force: 36,869 pounds
- Power: 345 horsepower
- Operating weight: 50,784 pounds
- Bucket capacity: 5.5 cubic yards
- Dump height: 10 feet 1 inch
- Breakout force: 47,210 pounds
- Power: 345 horsepower
- Operating weight: 56,868 pounds
- Bucket capacity: 6.3 cubic yards
- Dump height: 10 feet 8 inches
- Breakout force: 51,930 pounds
- Power: 380 horsepower
- Operating weight: 69,897 pounds
- Bucket capacity: 7.5 cubic yards
- Dump height: 11 feet 2 inches
- Breakout force: 55,303 pounds