Overview#
The 300 kW Kohler/Rehlko gaseous standby generator is sold as the 300REZXC (with sister designations 300REZXD / 300RZXD) — there is no Kohler model called "KG300." We've kept this URL because customers commonly search "Kohler KG300" when comparing 300 kW gas gensets, and we want them landing on accurate information.
The 300REZXC is one of the larger single-unit gaseous gensets in the North American market, powered by a Doosan-built 14.6L turbocharged-aftercooled V8 (Kohler PN GM64103). At this capacity, it competes directly with 300 kW diesel units for campus, hospital, and large commercial applications.
The 14.6L V8 platform#
- Doosan 14.6L V8, turbocharged and aftercooled — purpose-built stationary spark-ignition engine
- 8 spark plugs (V8) — ignition service is straightforward relative to the engine size
- Container enclosure option for large outdoor installations
- Paralleling-ready with the APM603 — common to see multiple units in array for campus distribution
When gaseous makes sense at 300 kW#
At this capacity, the diesel vs gaseous decision is genuinely close. Gaseous wins when:
- Air quality district restrictions penalize diesel emissions (Bay Area BAAQMD, South Coast AQMD)
- Site cannot accommodate a 1,000+ gallon diesel tank (space, environmental, permitting)
- Gas utility service is reliable and the facility accepts utility-dependent fuel supply
- Building owner preferences favor zero visible emissions for stakeholder perception
Our service experience#
The 300REZXC's 14.6L V8 is a serious stationary engine that demands experienced technicians. We recommend walk-in enclosures at minimum for any 300REZXC installation, and prefer container-style enclosures that allow full 360-degree access. The turbo-aftercooler system adds annual inspection items (charge-air cooler integrity, condensation drain, turbo oil drain lines) beyond what naturally-aspirated KG-class units require.
