Suspension options: Leaf springs vs. Air Bags vs. Air-ride
The Sprinter chassis is used for many different applications, it is a versatile vehicle, and there are many different reasons why someone would want to upgrade their Sprinter's suspension. Choosing a suspension upgrade can be one of the most important ways to make your Sprinter more comfortable, help level your ride, or to help reduce rocking, sway or wind drift. You can also use a suspension lift kit to gain ground clearance.
Keep in mind than many people and after market manufacturers use different terminology when talking about spring helpers, air ride, air bags, add a leafs, etc. An overload spring was a common term once used but the name was dropped due to the fact that no product will allow you to exceed the manufacturers Gross Vehicle Weight Rating. Again none of these products allow you to exceed Gross Vehicle Weight Rating. That rating is set by the vehicle manufacturer and many things come into play like the size of your brakes, wheel bearings, axles, and transmission strength. Vehicle stability and many other factors are all considered when your vehicle manufacturer sets the GVWR.
Sprinter vans come with rear leaf springs, so one option is to beef up or replace your leaf springs, all depending on what your goal is. Leaf springs can work alone as sent out by the factory or be upgraded with helper springs or air bags. Helper springs like the SumoSprings can help reduce sway, rocking and even some wind drift. They are a load holding product that add additional load support to your existing leaf springs. Depending on the product and situation they can also be used to help level your ride when sagging. SumoSprings are basically an airless air bag type system. The SuperSprings are also a helper type spring and work with your existing springs by adding an additional leaf to to the top of your spring pack. Helper springs are added in addition to your existing leaf spring pack and work together with your factory springs regardless of what configuration they come in. Some helper springs will also help to level a vehicle that squats in the back. Also some helper springs will have some adjust-ability but many do not.
Add - a - leafs also work in a similar fashion to a helper spring by adding additional leaves or blades under your existing spring pack. Add a leafs can add load support and or height increases depending on how they are set up.
An air bag system like the Boss air bags is similar to a helper spring but adds adjust-ability. They work in combination with your factory leaf springs in the rear. These are generally a bolt on type item that adds load support and when adding or removing air you can reduce sag or firm the ride. Many air bags can be set up with a compressor and gauge and will allow for adjust-ability form inside the cab.
Replacement springs for your Sprinter can be used for a variety of things and not all springs are the same or built for the same situation. These are a whole new spring pack that will replace your existing factory springs. Some spring packs are designed for additional load support and to help reduce sag and stabilize heavy vehicles. Replacement springs can be designed to lift the vehicle higher for more ground clearance which can help accommodate larger tires. Another spring can be designed to help soften the ride. The building of a softer riding spring takes additional steps, knowledge, and materials in order to work correctly. Any leaf spring replacement must be designed correctly so they will accommodate the load of the vehicle and last through all the wear and tear that a spring puts up with. Your whole vehicle is riding on them.
Another option is a true air-ride system like the Glide Rite 4-bag air ride system. These systems will remove the rear leaf springs altogether and replaces the steel factory springs with air bags. When you hear 4 bag, many times people think this is a front and rear air ride system. Almost all air ride type products target only the rear of the vehicle, so a 4 bag system will add two air bags just forward of the rear axle and two bags rearward of the axle. The air-ride system is considered the smoothest ride you'll find for your Sprinter van or RV. They are generally designed for a comfort ride but can also be set up to allow you to dump the air for lowering the rear loading height. Some have adjust ability while others maintain a factory set ride height. Air ride systems are generally the most complicated systems to install.
Leaf spring upgrades, helper springs, air bags, or an air-ride system can dramatically improve your performance, making your trip more comfortable, more relaxing, and more fun.
For a basic Sprinter suspension overview see our Sprinter Suspension 101 article here.