Hummer 2007 H3 - Manual (Page 254)

Design specifications required a minimum
gradeability of 60% (31 degrees) slope, with the
vehicle fully loaded, on high friction surfaces
with maximum vehicle speed not to exceed
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. Also, your vehicle should be able to traverse a
40% (22 degrees) side slope at 6 mph (9.7 km/h)
while fully loaded on high friction surfaces.
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