KDI and KDS under the DemoDays 2026 Spotlights
At DemoDays 2026, Rehlko highlighted the strengths of its KDI and KSD three- and four-cylinder diesel engine families, with a particular focus on their outstanding power density
At the previous edition of the DemoDays, the gasoline engine lineup captured almost all the audience’s attention. This year, however, the spotlight shifted primarily to Rehlko’s 3- and 4-cylinder diesel engines—the KDI and KSD families. Both engine ranges have been honored with the Diesel of the Year award.
HP: more than an upgrade
In our first report from DemoDays 2026, we covered the upgraded KDI 1903TCR, which has earned the new HP (High Power) designation. Now, let’s take a closer look at both sides of Rehlko’s diesel portfolio: KDI and KDS Engine Families.
“The best way to understand an engine isn’t to read about it—it’s to experience the machine it powers,” said Eric Fontaine, President of Rehlko Engines. “Demo Days reflects the way we work with our OEM partners every day. We engineer engines as part of a complete machine, helping our customers deliver greater productivity, reliability and value to the people who depend on their equipment.”
Alongside the introduction of the new KDI 1903 HP, attendees also experienced Rehlko’s complete diesel portfolio in action. The KSD family, Rehlko’s latest-generation diesel platform, continues to expand across construction, material handling and industrial applications, combining compact dimensions, excellent power density and low total cost of ownership.
More than a product showcase, Demo Days highlighted the close engineering collaboration between Rehlko and its OEM partners. Every machine on display demonstrated how engine integration, application engineering and shared product development contribute to higher machine performance, simplified installation and greater value for end users.
Benefits of KDS and KDI Engines
According to the officials, since its introduction, KSD has demonstrated significant customer benefits, including reduced fuel consumption, faster machine response and dependable performance in demanding operating environments. The event also featured applications powered by the established KDI 1903TCR, one of Rehlko’s most successful diesel engines. Designed for global off-highway markets, the engine combines robust heavy-duty architecture, high power density and Rehlko’s Smart After-Treatment System to meet the latest emissions standards while delivering excellent reliability and long service intervals.
Back to KDI 1903 HP
To summarize the engineering philosophy behind the project, let’s take another look at the Rehlko KDI 1903 HP. The company presents it as a benchmark in the high-power three-cylinder diesel segment, thanks to its combination of compact dimensions and outstanding power density. Delivering up to 50 kW, the engine offers a higher power-to-size ratio than many competing three-cylinder engines and even outperforms several four-cylinder alternatives while maintaining a significantly smaller installation footprint.
According to Rehlko, the slight increase in engine packaging required to achieve the 50 kW output is more than offset by the performance gains. The compact design enables OEMs to maximize available space, simplify machine integration and downsizing, and improve overall machine efficiency without compromising productivity.
