Dobinsons 2.2" IMS vs. Bilstein 5100: Which Is Best for Your Vehicle?

There are many options to choose from when picking the shocks and struts that are best for your needs. Dobinsons and Bilstein both have relatively affordable options that offer a smoother, more controlled ride quality. This article will help you decide which is best, based on what you demand from your truck or SUV.

Dobinsons 2.2" IMS Front Struts

Dobinsons IMS front struts feature a 2.2-inch body diameter, a threaded lower perch ring, and different coil spring options. The larger the body diameter, the more oil cooling the strut is able to provide.

A threaded lower perch provides infinite adjustability up to 3 inches of lift, and typically means the height can be adjusted while the struts are mounted on the vehicle. Aftermarket spring options allow more height with less preload, and are available to support stock-weight front bumpers or aftermarket winch-style bumpers.

When paired with the recommended Dobinsons springs, the ride quality is much improved over stock because the front struts are functioning as intended, with the correct valving and spring poundage, without sacrificing load capacity. Dobinsons IMS struts support added weight and are built tough to take off-road abuse.

The Dobinsons IMS strut, when paired with Dobinsons springs, costs more than the Bilstein 5100. But the tuned ride quality that can be built to support added weight makes the Dobinsons a better choice over the Bilstein 5100.

Bilstein 5100 Front Struts

Bilstein 5100 front struts typically feature a 1.8-inch body diameter, snap-ring lift-height settings, and often re-use the OEM springs. A smaller body diameter provides less oil cooling, so the strut has to work harder to manage heat.

Snap-ring height settings mean the desired lift height has to be determined before installation. The lift settings are predetermined, with a series of stepped height notches. To change the height, the struts must be disassembled every time to remove the coil springs and move the snap-ring up or down to the next available height-setting notch.

The valving is paired with whatever trim-model springs your vehicle came with, which can deliver mixed results. With this combination there is no accommodation for heavier aftermarket front bumpers. Because the Bilstein 5100 does not allow many spring and strut variation combinations, it cannot adequately support added weight and continual abuse from off-roading.

That said, the Bilstein 5100 offers an exceptional budget-friendly entry point for leveling or mild lifts, and rides great for the price on-road.

Which Is Best for Your Vehicle?

When deciding between Dobinsons IMS and Bilstein 5100 struts, Dobinsons takes the lead for enthusiasts who prioritize off-road capability, by supporting loaded comfort from added weight off-road.

The Bilstein 5100 is for those looking for a mild lift with mainly stock components, who drive mainly on-road and off-road on light, relatively flat trails.

Frequently Asked Questions

What is the main difference between Dobinsons 2.2 IMS and Bilstein 5100 struts?

The Dobinsons IMS uses a larger 2.2-inch body, a threaded lower perch for infinite height adjustment up to 3 inches, and offers different spring options to support added weight. The Bilstein 5100 uses a smaller 1.8-inch body with predetermined snap-ring height notches and typically re-uses your factory springs. Dobinsons is the more tunable, load-capable strut; the 5100 is the budget-friendly entry point.

Can I adjust ride height with these struts while they are on the truck?

With the Dobinsons IMS, yes. The threaded lower perch lets you adjust height, typically while the struts are mounted on the vehicle, up to 3 inches of lift. The Bilstein 5100 uses fixed snap-ring notches, so the lift height must be set before installation, and changing it means disassembling the strut to move the snap-ring to a different notch.

Which is better for a truck with a heavy aftermarket or winch bumper?

The Dobinsons IMS. Its aftermarket spring options are available to support stock-weight or heavier winch-style front bumpers without sacrificing load capacity. The Bilstein 5100 does not accommodate heavier aftermarket front bumpers, because it does not allow the same range of spring and strut combinations.

Is the Dobinsons IMS worth the extra cost over the Bilstein 5100?

It depends on how you use your truck. The Dobinsons IMS, paired with Dobinsons springs, costs more than the 5100, but it delivers a tuned ride quality that can be built to support added weight and take off-road abuse. If off-road capability and load support matter to you, the Dobinsons is the better strut. If you want a mild lift on a mostly stock, on-road truck, the 5100 is a great value.

Which strut should I choose for mostly on-road driving?

The Bilstein 5100. It is an excellent budget-friendly choice for leveling or a mild lift, and it rides great for the price on-road, especially on a mostly stock truck that sees light, relatively flat trails. Step up to the Dobinsons IMS if you want real off-road capability and the ability to support added weight.