Aluminum vs Steel on an offroad rig:
I suggest aluminum anywhere above the midline of the rig(headlights and above). Things up here dont tend to get hit very often and if they do its not very hard. This ties back into the low center of gravity thing.
Bumpers: kind of dealers choice here. You know how you drive. If you hit your bumpers a LOT, I would go with steel. If you occasionally tap a corner dropping off rock than aluminum will hold up for years.
Sliders: Steel. You will hit them...often. If they deflect, that means your body just took a hit as well and you spend money on sliders to prevent that, right?
Skid plates: These can go either way. If you are constantly dragging your belly over sharp rocks, steel is your friend. It will last longer and not gouge very easy. If you hit it a few times here and there, save the weight and go aluminum. The skids are all supported by your steel chassis so they will take quite a bit of abuse.
Always keep your vehicles power to weight ratio in mind. Adding weight lowers your fuel economy and actually makes it harder to climb obstacles on the trail. Also, Weight breaks parts. The lighter you can keep the rig, the less headaches you will have. Look into options like a front receiver if you dont want to carry a winch on your daily commute as well. You can "What if" your rig to death. The vast majority of the rigs here are set up for overland travel, not hardcore rock crawling. Save weight ANYWHERE you can.
