Hummer H2 2004 Owner's Manual page 244

The HUMMER H2 has an approximate approach
angle (A) of 42° and a departure angle (B) of 37°,
depending on suspension packages.
4-24
Design specifications required a minimum gradeability
of 60% (31°) slope, with the vehicle fully loaded, on
high friction surfaces at 6 mph (9.7 km/h). The vehicle
is expected to traverse this grade only for short
durations. Never stop and idle the vehicle or park it on
this grade.