Construction Solutions: Cat® Diesel Electric Machines

13 July 2021

Diesel electric drive machines are gaining traction and have the potential to decrease load cycle times, increase maintenance intervals, lower emissions and reduce fuel costs. There can be big benefits, but the key is to determine whether this equipment is right for your job site.

How does it work?

The Cat diesel-electric powertrain works similarly in both the D6 XE dozer and 988K XE wheel loader. They both have a diesel engine and liquid-cooled electrical systems with electric generators mounted directly behind the engine.

In the dozer, the power from the engine is converted to electricity by the generator, which powers the electric motor. It then sends power through inverters to the electric control module and then to the final drives which move the tracks.


In the wheel loader, the power from the engine is converted to electricity by the switch reluctance (SR) generator, then goes through the power inverter to the switch reluctance (SR) electric-drive motor which powers the driveline to the wheels.

How does it work?

The benefits

Investing in premium upfront may not be cost effective if you're going to run the machine for a year and then sell, as most cost savings of an XE machine are realized over the long term through total cost of ownership. Here are some other benefits of diesel electric drive.

· Fuel savings

In addition to the productivity boost, fuel savings is where the payback on investment in the XE machine is significant. For example, if the 988K XE machine consumes 47 litres of fuel per hour, and the conventional counterpart consumes 65 litres per hour, with fuel costs of $1 per litre, the savings over 20,000 hours of ownership would be $360,000.

· Lower emissions

The greenhouse gas reduction that comes with fuel burn reduction may also be an important factor for operators, particularly for work in regions that require bidding contractors to use the most environmentally friendly machines.

· Productivity

Caterpillar gathers telematics data from machines around the world which it can then use to analyze average cycle times of that model - measuring productivity. The data on cycle times for the 988K show an average complete cycle time of 0.61 minutes for the conventional machine versus 0.58 minutes for the XE model. What looks like a small gain for a single cycle adds up significantly over the working life of the machine. The D6 XE realizes similar productivity gains.

Finning is the world's largest Caterpillar dealer, selling, renting and providing parts and service for equipment and engines to customers across diverse industries, including mining, construction, petroleum, forestry and a wide range of power systems applications. We operate in Western Canada, South America, and UK and Ireland.