I am more interested in aluminum vs steel. Not for weight purpose but so I don’t have worry about rust. Haha.
Of course aluminum doesn’t rust. It can’t. Rust is iron oxide and aluminum has no iron in it. Since aluminum cannot rust, the internet would have us believe it’s a miracle metal. It isn’t. While aluminum can’t rust, it does corrode. Although aluminum is lighter than steel, it isn’t as abrasion resistant.
In my experience with my two door JK on 35s, common points of contact are front & rear bumpers, rocker panels, control arms, the aftermarket drop down control arm brackets, axle diffs and the transmission crossmember.
When armoring up, I suggest getting rock sliders first (to keep the rocker panels from getting damaged), then bumpers, then a beefed up crossmember. I’m on my second factory crossmember and it’s ready bent, buckled & distorted.
I’ve run trails with and without skid plates. I found the plates would drag across rocks the Jeep would clear without them.