The various rock slider designs you will encounter all have specific pros and cons. In this post I will cover the main areas of trade off and hopefully get you closer to the right slider for your rig. The following questions are important to ask yourself before you make your decision.
Are you going to be on the rocks often or is this mainly insurance for less aggressive overlanding?
Do you have kids or less mobile individuals that will be in and out of your rig?
Do you have any specific sliders that you just love the looks of?
Make Sure They're Sliders
When picking a slider the first thing you need to do is ensure that the slider is truly a slider. Many step bars out there are not designed to support the weight of the vehicle and under that kind of load will buckle. If all you need is something to get in and out of your vehicle a step rail of this type may be fine for you.
Box Steel and Tube
Depending on the vehicle you have you might only have a few sliders to choose from to over a dozen. Most sliders are constructed of some sort of box steel that is the main slider protection and tube steel is welded to this to protect the roll pan and side of vehicle.
Here is a good example of what I am talking about.
There are also sliders that are all box steel but I don't see too many of these.
DOM vs HREW
Not all tubing is created equal. The manufacturing process determins the strength. DOM and HREW are choices that some slider manufactures offer others are one or the other. It is important to know which you are looking at so you are sure to be comparing apples to apples. Bottom line is DOM is stronger. If you know you are going to be bashing some rocks or like the peace of mind then DOM is the way to go.
Here is a description I found concerning the differences between DOM and HREW from (The Steel Tube Institute)
Hot-Rolled ERW (HREW) is rolled into a tube at elevated temperatures. This process produces more malleable (easier to form) tubing, which is not as strong, covered with scale, and not as uniform in dimension as cold-rolled tubing. It is, however, the most inexpensive option.
Cold-Rolled ERW (CREW) follows the same manufacturing process, except at room temperature. Compared to HREW, CREW is stronger because of the improvement in the crystal lattice structure from improved grain size, shape, and orientation. As a result of these characteristics, the finished product is straighter, has a much smoother and more uniform surface finish, and is made to tighter, more consistent dimensions.
Drawn-Over-Mandrel (DOM) tubing basically starts its life as CREW. After shaping, the weld is tested for integrity and cut to length for further processing. The tube gets cleaned and annealed and is then drawn through a series of dies and over mandrels. This reduces the diameter of the tube and thins its walls to the required dimension. Close dimensional accuracy is achieved through tight control of both outside and inside diameters. Drawing improves the tube’s concentricity, tensile strength, hardness and machinability. The cold-drawing process creates a uniform, precision product with substantially improved tolerances; superior surface finish and tensile strength; increased hardness; and good machinability.
Bump Out vs Straight
A bump out is designed to push the vehicle away from the rock as it reaches the rear of the vehicle. This can pivot the vehicle and keep the rock from hitting the tire or rear end of the vehicle. I am sure this can be a positive but not sure how often this will matter. Probably a nicer feature if you are rock crawling a lot and maybe less of one if your more of an overlander. However, it does look pretty cool in my opinion.
Angled with Bump Out
Straight without Bump Out
Angled vs Level
Angled sliders give a little more protection a little higher up on the rollpan. The angle can also serve to slide/picot your vehicle away from a rock. The angled also looks pretty cool in my opinion. The real advantage of the straight is it is more useful as a stable step surface. I think angled is the way to go for those that are going to be in more serious rock sliding situations or just like how they look.
Step vs No Step
Whether angled or straight many manufacturers offer diamond plate or a non-skid plate that covers the opening of the rock sliders. This makes the slider more useful as a step. Some also offer a plate cover just over the bump out. If you opt for the bump out the open area is easy to slip your foot through which could be pretty nasty. If you have younger children or for older folks having a non-slip surface without places for you feet to slip into is especially valuable. The only down side to covering the slider that I can think of, is it will be an easy place for mud to accumulate and not necessarily easy to clean up.
Paint vs Powder Coat
Powder coat is a low maintenance highly durable coating until it's not. Once a slider is slide over some rocks and the coating is cracked or scraped then it will likely be a little bit of a pain to keep nice. Spray paint won't always bond to the damaged powder coat and sometimes the coating will tend to flake and crack after the initial compromise. For this reason many opt for spray painting aka rattle caning. Everytime you hit a rock just pull out your spray can and your good to go. Again this is a personal choice but if you suspect you will be balancing on rocks every trip then spray canning is the way to go. If your rock sliders are good insurance for you mild offloading and overlanding powder coating is probably the best choice for longevity.
A few sliders have unique mounting styles that have a U bracket around the frame that allow for max smoothness over rocks. Most are attached with heavy U-bolts around the frame. The more mounts the better but in most cases I don't think the differences in mounting are too pronounced to have an impact on your choice.
I have only looked at sliders for Land Cruisers and 4Runners and seen many for Jeeps in my research. On the 4Runners there are over a dozen to choose from and maybe many more. On Land Cruiser 100 series there are maybe a half dozen. For 100 series land cruisers most sliders are within $100 of each other and about $1000. For 4Runners I have seen them from $500-$1000. In the end I suspect you get what you pay for. I would recommend zeroing in on all your other requirements first and making the cost comparison the last step. We spend so much on our rigs getting the best for your needs is the best route.
Most of these factors are based on how much you expect to actually be sliding on rocks vs accessibility in your rig. Answer all the key questions up front and that should help you hone in and a few. Check reviews and user experiences on forums also. There is generally tons of helpful info on sites like ih8mud.com or http://www.toyota-4runner.org
A few manufactures I have looked at that get pretty good reviews:
If you have a 4runner this post gives an awesome run down of different brands