Manufacturer-published reliability figures tell you how a generator should perform. This report shows how diesel generators actually performed across a live, multi-operator mission-critical portfolio, built from real operating and failure records.
The MCIM Diesel Generator Reliability Benchmarking Report compares five generator platforms on mean time between failures, failure rate, resolution time, and failure modes, with 95% confidence ranges behind every figure.
The dataset
- 3,072 diesel generators in scope
- 2,289 asset-years observed
- 373 measured failures
Four findings that stood out
- Caterpillar leads on every reliability measure: the longest MTBF, the lowest failure rate, and the fastest resolution time in the dataset.
- The Cummins gap is real, not sampling noise: its MTBF range doesn’t overlap Caterpillar’s, and failures concentrate in cooling and fuel systems.
- Resolution time varies more than the machines do: MTTR runs from 188 to 445 hours across manufacturers, a 2.4x spread.
- Brand-new units drove most of Kohler’s failures: thirteen newly installed units in their first five months of service account for 23 of Kohler’s 39 measured failures.
What it means for your next purchase
The report closes with four conclusions buyers can act on, ordered by how strongly the data supports them. They cover weighing resolution time alongside failure frequency, putting reliability effort at the front of asset life, scrutinizing the systems around the engine, and specifying and verifying consumables.
“The coolant is watered down, almost looks like pure water, incorrect color for proper cat coolant. Needs to be flushed and the system filled with cat specific coolant.”
Planned maintenance finding quoted in the report
Who it’s for
Data center operators, facilities and critical environment leaders, and procurement teams specifying, sourcing, or maintaining standby diesel generators.
Figures reflect recorded operating experience across multiple operators and aren’t statements about product quality in general. This report is independently prepared by MCIM and isn’t sponsored by, endorsed by, or affiliated with any manufacturer named in it.
