Hummer H3 (USA / CAN)

Coolant capacity & service interval

Hummer H3 (USA / CAN) coolant capacity ranges from 9,5 to 13,5 liters. Service intervals include checks every 12500 km or 6 months and changes every 240000 km or 60 months. The data covers 3 configurations.

The configuration chart below lists fill volumes and service intervals for each engine and trim variant.

TypeSpecifications
H3 5.3 V8 (2008-2010)
  • Use: Normal
  • Capacity 13,5 liter
  • Check 12500 km/ 6 months
  • Change 240000 km/ 60 months
H3 3.7 (2007-2010)
  • Use: Normal
  • Capacity 9,5 liter
  • Check 12500 km/ 6 months
  • Change 240000 km/ 60 months
H3 3.5 (2005-2007)
  • Use: Normal
  • Capacity 9,5 liter
  • Check 12500 km/ 6 months
  • Change 240000 km/ 60 months

Additional Notes

  • The Hummer H3 3.5 and H3 3.7 engines share an identical cooling system capacity of 9.5 liters, despite being distinct engine displacements produced across different model year ranges.
  • The H3 5.3 V8, introduced for 2008-2010, carries a notably larger cooling system capacity of 13.5 liters, reflecting the greater thermal load generated by a V8 engine compared to the inline five-cylinder configurations.
  • A 4-liter difference in coolant capacity separates the V8 from the inline five-cylinder variants, which in practical terms means a meaningfully larger volume of fluid must be drained, flushed, and refilled during a full cooling system service on the V8.
  • Across all three engine configurations, the coolant change interval is set at 240,000 km or 60 months under normal use conditions, placing the H3 in a long-life coolant service category.
  • The 60-month change interval corresponds to a five-year cycle, meaning a vehicle kept in continuous service from new would reach its first coolant change well before the odometer-based threshold in many typical usage patterns.
  • All three configurations share a coolant level check interval of 12,500 km or 6 months under normal use conditions, establishing a semi-annual inspection cadence independent of engine size.
  • The H3 3.5 covers model years 2005-2007, while the H3 3.7 covers 2007-2010, indicating a one-year overlap in 2007 during which both engine options were available in the lineup.
  • The 9.5-liter capacity listed for both inline five-cylinder engines represents the full cooling system fill volume, which is the figure relevant to a complete drain-and-refill service rather than a partial top-off.

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