What Is Toyota's X-REAS Suspension, And Which 4Runner Models Use It?

Looking through Toyota's comprehensive line-up of current SUV models, it's clear to see which models are targeted towards off-road use and which have been designed primarily for the asphalt. Take, for example, the 2025 Toyota 4Runner, a model which we tested extensively earlier in the year. The elevated ride height, all-terrain tires, and bulky bodywork indicate that it's a vehicle designed for the path less trodden. Other models, such as the evergreen RAV4 and diminutive Corolla Cross, are lower, have more car-like proportions, and are clearly intended for regular commuting as the priority.

However, Toyota has a suspension system that allows models like the off-road-oriented 4Runner to perform just as well on the road as off of it. The system is called X-REAS, which stands for Cross Relative Absorber System. While it doesn't feature on sixth-gen models, it was available on 4Runner models between 2003 and 2024 on select trim levels such as the Limited.

In short, the X-REAS suspension is a system that connects the front and rear absorbers via a series of diagonal tubes. So, the nearside front shock absorber links to the offside rear, and vice versa. In the middle of these tubes is a central control absorber, which balances the pressure of the two connected shock absorbers by regulating the flow of hydraulic oil through a floating piston mounted within. X-REAS automatically balances the damping of all four wheels, allowing for confidence-inspiring performance while on the road without hindering off-road performance.

As far as we can tell, Toyota no longer uses X-REAS on current 4Runner models. It last featured on the fifth-gen 4Runner's Limited and TRD Sport trims. According to owners, the system can be useful, although it has been known to fail on older models. The problem here is that the X-REAS system's complexity compared to a traditional suspension setup makes it expensive to repair or replace. Thus, some may wish to steer clear of used models with it equipped. 

Fortunately, it is possible to determine whether a 4Runner has the X-REAS system installed or not. To do this, it's easiest to examine from the rear wheel well. From atop the shock absorber, you will be able to notice a soft line connecting the shock absorber to the X-REAS tube system. You can also spot the central control absorber from beneath the vehicle. If you see either one, you're looking at a model with X-REAS. Not all 4Runners were sold or optioned with the system, so a visual check is often necessary. It's easy to tell if your car needs new suspension, but complex systems like this aren't necessarily easy to work on, so some owners opt to replace worn-out X-REAS setups with something a little more traditional.