Caterpillar · Cat D-Series GC (Diesel)

Cat D1250 GC

1250 kW standby / 1135 kW prime · Diesel · Liquid-cooled

1250 kW diesel standby generator from Cat's GC value-engineered line. C32B V-12 engine with simplified controls for mission-critical standby.

Standby power
1250 kW / 1135 kW prime
Voltage options
277/480V, 346/600V, 4160V
Frequency / Phase
60 Hz · 3-phase
Engine
Caterpillar C32B · 32.1L
EPA / Emissions
Tier 2
standbyData CentersHealthcareCommercialparalleling-array
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Overview#

The Cat D1250 GC is a 1,250-kilowatt diesel standby generator — the flagship of Cat's GC value-engineered line. It uses the evolved C32B engine to deliver 1.25 MW from a single unit, making it the highest-power GC model available.

C32B: evolved performance#

The C32B is Cat's next-generation version of the legendary C32 — same 32.1L V-12 block with enhanced fuel injection, improved turbocharging, and upgraded electronic controls. The D1250 GC brings this evolved platform to the GC line, delivering substantially more power than the C32-based D1000 and D1100 GC models.

Our service perspective#

The D1250 GC uses the C32B platform, which shares core architecture with the standard C32 but includes evolved components. Service procedures are largely identical, with some differences in fuel injection and turbocharger systems. Cat dealer support for the C32B platform is strong and growing as it powers the flagship D1500 as well.

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Estimate runtime for the Cat D1250 GC

Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.

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Estimated runtime

3.0 hours(0.1 days)

Fuel consumption ≈ 67.50 GPH at 75% load. Estimate based on industry-typical 1800 RPM standby curves (≈0.07 GPH/kW at full load). Actual consumption varies by engine, ambient temperature, fuel quality, and tuning.

Frequently Asked Questions

What is the Cat D1250 GC?
The D1250 GC is the largest model in Cat's GC value-engineered line — 1,250 kW from the evolved C32B V-12 engine. It delivers the highest single-unit power available in the GC package for data centers and hospitals requiring 1.25 MW per unit.
What is the C32B engine?
The C32B is Cat's evolved version of the C32 — same 32.1L V-12 block with enhanced fuel injection, improved turbocharging, and upgraded electronics that extract up to 50% more power. It powers both the D1250 GC and the flagship D1500 genset.
How does the D1250 GC compare to the D1500?
Both use the C32B engine. The D1500 is Cat's standard (non-GC) flagship at 1,500 kW with advanced EMCP controls and full paralleling. The D1250 GC is the GC value-engineered version at 1,250 kW with simplified controls and lower cost.

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