Overview#
The Kohler 175REOZT4 is a 150-kilowatt standby (139 kW prime) EPA Tier 4 Final diesel mobile trailer generator powered by a John Deere 6068HG550 engine at 1800 RPM. This is the largest model in the REOZT4 mobile trailer series, and shares the same engine, enclosure, and trailer platform as the 145REOZT4 — the primary differentiator is the larger Kohler 4S12X alternator (versus the 4R13X in the 145REOZT4), which provides the additional output capacity.
Like the 145REOZT4, the 175REOZT4 uses John Deere's SCR/DEF system to achieve Tier 4 Final compliance. The 6068HG550 engine in this application is rated to 180 kW (241 HP) maximum output, giving the alternator headroom to deliver 150 kW standby reliably. The Kohler 4S12X alternator is capable of 480 kVA peak motor starting, making this unit well-suited for loads with high inrush current requirements.
The 175REOZT4 ships with a 1,045-liter (276-gallon) integral diesel tank and 44.2-liter (11.7-gallon) DEF tank, providing 24-hour runtime at prime rating. The dual-axle trailer is rated at 6,000 lb. per axle, DOT and Transport Canada compliant. Sound level is rated at 71 dB(A) at 7 meters.
Specifications#
| Spec | Value |
|---|---|
| Standby Power | 150 kW |
| Prime Power | 139 kW |
| Voltage | 120/208V, 120/240V, 277/480V, 347/600V |
| Frequency | 60 Hz |
| Engine | John Deere 6068HG550 |
| Cylinders | 6 inline |
| Displacement | 6.8 L (415 cu. in.) |
| Aspiration | Turbocharged, Charge Air Cooled |
| Emissions | EPA Tier 4 Final (nonroad, SCR+DEF) |
| RPM | 1800 |
| Alternator | Kohler 4S12X |
| Fuel | Ultra Low Sulfur Diesel / HVO / RD |
| Cooling | Liquid (unit-mounted radiator, 45°C ambient) |
| Fuel consumption — 75% load | 8.5 gph (standby) |
| Fuel consumption — 100% load | 11.2 gph (standby) |
| Diesel tank | 276 gal (1,045 L) — 24 hr minimum runtime |
| DEF tank | 11.7 gal (44.2 L) |
| Sound level | 71 dB(A) @ 7 m (prime, full load) |
| Dimensions (L x W x H) | 150.9" x 46.8" x 90.3" |
| Controller | Decision-Maker 3500 |
Service & Maintenance#
Kohler's published maintenance schedule for the 175REOZT4 / John Deere 6068HG550 engine:
| Service | Interval |
|---|---|
| Oil and filter change | Every 250 hours or 12 months |
| Fuel filter replacement | Every 500 hours |
| Air filter inspection/replacement | Every 500 hours |
| Coolant flush | Every 3,000 hours or 5 years |
| DEF system inspection | Per John Deere/Kohler schedule |
| Load bank test | Every 12 months (NFPA 110 requirement) |
| Major overhaul | Every 15,000 hours |
The 6068HG550 oil pan holds 28.5 liters (30.1 quarts) with filter. The starting system is 24-volt with two 400 CCA batteries. DEF level and quality should be checked at every service visit and before each extended deployment. Use only AUS32 DEF per ISO 22241-1.
Common Failure Modes#
The 175REOZT4 shares the same failure mode profile as the 145REOZT4. DEF quality alerts and NOx sensor faults are the most common system-level issues. The SCR catalyst in units operated primarily at very light loads is susceptible to sulphate deposits; regular loaded exercise at 75%+ load significantly extends catalyst life.
Turbocharger wear (power loss, elevated smoke) typically appears after 12,000+ hours. Fuel injector fouling from degraded diesel is a risk for units sitting between seasonal deployments; fuel polishing or full fuel replacement before return to service is recommended if diesel has been stored over 6 months. Battery replacement on a 3–4 year cycle is standard preventive maintenance.
Our service experience#
OnPoint Generators provides installation, maintenance, load bank testing, and emergency service for Kohler industrial generators throughout Northern California and the Central Valley. The 175REOZT4 is the top-of-range mobile trailer option in the REOZT4 series and is commonly specified for large-scale temporary power installations requiring a single towable unit above 130 kW. Its shared platform with the 145REOZT4 means our field teams can service both models with the same parts inventory, and the John Deere 6068 engine is supported through both Kohler/Rehlko and John Deere dealer networks regionally.
FAQ#
What engine powers the Kohler 175REOZT4?#
The 175REOZT4 uses a John Deere 6068HG550 diesel engine — a 6-cylinder, 6.8-liter turbocharged and charge-air-cooled engine running at 1800 RPM, rated to 180 kW (241 HP) maximum.
Is the 175REOZT4 EPA Tier 4 Final certified?#
Yes. The 175REOZT4 is Tier 4 Final EPA-certified for nonroad applications using SCR with Diesel Exhaust Fluid. A dedicated 11.7-gallon DEF tank and quality sensor are integrated into the unit.
How does the 175REOZT4 differ from the 145REOZT4?#
Both models use the same John Deere 6068HG550 engine and identical enclosure dimensions. The 175REOZT4 uses the larger Kohler 4S12X alternator versus the 4R13X in the 145REOZT4, delivering 150 kW standby versus 130 kW. Peak motor starting kVA is 480 kVA for the 175 versus 540 kVA for the 145 at 480V.
What is the sound level of the Kohler 175REOZT4?#
Per Kohler published specifications, the 175REOZT4 is rated at 71 dB(A) log average at 7 meters with full load at the prime rating.
