2006 Hummer H3 Owner's Manual - Page 222

Roll Your Tires Over Large Rocks Do not straddle large rocks; drive over them, letting the tire envelop the rock. The tread of the tire is thicker and tougher than the sidewall of the tire and is more resilient to impact than underbody components. Log Crossing Using the proper technique, your vehicle will cross logs up to 10 inches (25.4 cm) in diameter. Approach the log at approximately a 15 degree angle (A) with the transmission in FIRST (1) and the transfer case in Four-Wheel-Low Lock and "walk" your vehicle over, one tire at a time. As with all obstacles, face your tires perpendicular to the object for best traction and tire life. It may be necessary to modulate your brake pedal and accelerator to avoid spin-out. Ease the vehicle down from the log with your brake. 4-26