Saucony Xodus Ultra 4 review

Based on our testing, the Saucony Xodus Ultra 4 is a strong choice for:

• Those seeking a trail shoe that delivers great energy return and feels efficient over long distances.
• Anyone racing ultras who dislikes the feel of a carbon plate but still wants a responsive ride when the legs start to give up.
• Trail runners who avoided previous versions due to the outsole. Now that it finally uses Vibram Megagrip, that excuse is gone.
• Lovers of PWRRUN PB foam who want a similar lively sensation adapted for mountain terrain.

From our perspective, we do not recommend the Xodus Ultra 4 if you have wide feet. After testing, we discovered that its tapered toebox feels limiting during long efforts, especially ultras, and we believe there are better alternatives like the Nike Zegama 2 or the Topo Ultraventure 4.

We also consider the heavy build a drawback. We felt that the shoe loses that agile, fast-paced feel many modern trail runners enjoy. If weight matters to you, we do not recommend this model, and we suggest the HOKA Challenger 8 as an alternative.

We discovered that the Saucony Xodus Ultra 4 delivers the same shock absorption in both the heel and forefoot, scoring 127 SA in each area, which is a very solid outcome and fits the shoe’s name.

But this is quite unusual, as most shoes (except zero-drop models) score higher in the heel. Well, the dual-foam setup explains it: EVA sits mostly in the heel while Pebax dominates the midfoot and forefoot, and this premium foam offers more shock absorption per inch, making both measurements match even with less stack height in the forefoot.

One of the biggest strengths of the Xodus Ultra series has always been energy return, and we discovered that version 4 keeps the ball rolling with 64.9% in the heel and an impressive 72.4% in the forefoot.

Again, you see a big difference that is not common at all between heel and forefoot, right? It happens for the same reason stated before, as PWRRUN PB (Pebax) offers excellent bounce in the forefoot, while having more PWRRUN (EVA) in the heel slightly reduces the energy that comes back from the shoe.

We measured the stack height of the Xodus Ultra 4 at 37.6 mm, which is quite high for a trail shoe even if it feels less extreme compared to modern road running shoes.

And it's fine for us. In our view, it's clear that trail shoes need more stability—especially for lateral control and secure descents—so this height seems like a sensible choice.

The forefoot sits firmly in the max-stack category for trail shoes at 31.1 mm, and it’s another clear reason we think this model is ideal for midfoot and forefoot strikers, as they will obtain a rare mix of superb cushioning and strong energy return in the mountains.

Saucony states an official 6 mm heel-to-toe drop for the XU4 and we found 6.5 mm, which is impressively close and confirms a very balanced drop that works great for trail running, handling all footstrikes with a smooth feel.

And since we use the photo of the sliced shoe for this test, we will take the opportunity to talk about the midsole design. As we found, most of the midsole of the Xodus Ultra 4 is white PWRRUN PB with a strong presence through the midfoot and forefoot, while the heel features a bit of burgundy PWRRUN that slightly reduces shock absorption and energy return, although it boosts durability... and that’s why it’s there!

The main star of this shoe is the PWRRUN PB layer, a superfoam from Saucony that is a fan favourite across the board and appears in best-selling models like the Endorphin Speed 5.

We discovered it comes here with a slightly plush sensation for a trail shoe at 17.0 HA, but what matters most is that it keeps that familiar, bouncy character we’ve enjoyed since Saucony introduced it back in 2020 during the pandemic.

The secondary layer in this shoe is the EVA-based PWRRUN, which surrounds the PWRRUN PB throughout the whole shoe but sits mostly in the heel.

We found that it’s a firmer EVA, measuring 23.0 HA in our durometer, and it does its job well by protecting the Pebax from early wear while adding stability to the heel area.

The rocker on the Xodus Ultra 4 is clearly aggressive in the forefoot and heel. In the front of the shoe, the curve starts early and rises sharply, creating a smooth forward roll that helps you transition quickly. It’s designed to reduce calf load and make long trail miles feel easier and more efficient, especially when fatigue starts to rise.

We think fit is crucial in every trail shoe, especially in models made for ultra distances where you may spend dozens of hours wearing them.

To get a clear answer, we created a gel mould of the Xodus Ultra 4 and we discovered 96.6 mm in our first reading, placing it on the roomier side—so let’s keep going.

Our second measurement was less encouraging for wide-footed runners, as it returned 71.6 mm. This is definitely a tapered toebox design and makes the shoe less appealing for those who prefer extra space for their toes.

In our last measurement, we verified that the Xodus Ultra 4 leans toward a secure fit rather than a roomy feel.

With only 24.5 mm of vertical clearance, it suits runners who prefer an upper that locks the foot in place, but it’s less ideal for high-volume feet.

Saucony finally partnered with Vibram and selected the dependable Megagrip rubber with Traction Lugs. Thanks to that, the Xodus Ultra 4 excelled in our grip test, earning an impressive 0.72 score that delivers confident traction across a wide range of conditions.

We measured the lugs at only 3.5 mm, which fits the intended use of this shoe as a strong option for US-style, flat-ish ultra trails.

It naturally limits versatility on technical terrain, but running 20 or 30 miles on easy ground with very deep lugs feels awkward, and we discovered that the new Vibram rubber featuring Traction Lug technology helps balance things nicely.

The outsole of the Xodus Ultra 4 includes full-length rubber coverage except for a small cutout that improves flexibility. This is great news because it offers better durability than many rivals and, even more, this is the first Xodus Ultra to use Vibram rubber. This outsole also showed that, unlike the Xodus Ultra 3, there is no rock plate anymore in this shoe, and we think it feels like the right decision.

The lug design is quite simple, and we actually liked that. Brands often overcomplicate outsoles with weird patterns, but the classic chevron shape with proper orientation in the heel and forefoot usually works best for a shoe made for easy, non-technical trails.

Despite its substantial stack height and full outsole coverage, we recorded a very reasonable 15.3N in our 30-degree bend test, keeping the shoe comfortable and suitable for easy paces or even hiking.

There are some downsides with this update too. At 11 oz or 312g, this update is heavier than its predecessor because of the new Vibram outsole and higher stack height.

It’s not a deal-breaker as the difference is minimal, but it starts to feel a bit heavy for long efforts, and we think Saucony could improve this in the future by using the Litebase version of Megagrip or reducing the amount of PWRRUN foam.

The thick upper of the Xodus Ultra 4 contributes to its higher weight, but it also brings clear durability benefits thanks to its ripstop mesh, which helps prevent early tearing.

In our breathability test, we measured a solid 3/5 score. That might feel average for a road shoe, but for a trail model it’s a well-balanced result and perfectly acceptable for long sessions on mixed terrain.

Saucony found a nice middle ground between comfort, stability, and airflow by adding targeted ventilation holes, especially in the toebox.

Under the microscope, we also confirmed the presence of reinforced ripstop threads that boost protection and structure.

The upper could definitely be lighter, but if weight is not a priority for you, it checks all the important boxes. Build quality feels solid, and the heel area delivers a very comfortable experience.

The Xodus Ultra 4 delivers a very stable feel underfoot by combining several supportive elements. The midsole is wider than usual, the PWRRUN carrier foam adds structure, and the heel area is quite stiff, making the ride of the XU4 consistently predictable.

The outsole cutout adds a bit of flex in the heel area, but it isn’t enough to stop the shoe from earning a max torsional-rigidity score of 5/5. This result was fully expected with the thick midsole and the full rubber coverage.

The heel counter is also on the stiff side, and we struggled to move it during testing. That resulted in a 4/5 score, which is one step higher than what we usually see in trail running shoes.

When looking at the dimensions of the Xodus Ultra 4, we discovered that Saucony kept the wider forefoot and heel from version 3, and we’re glad to see that.

Compared to the much narrower Xodus Ultra 2 (112.5 mm), the evolution remains clear. This year, the shoe measures 116.7 mm in the forefoot, which is 1.3 mm more than last year and still wider than the average trail shoe.

Like many recent trail releases, the heel has become wider and now measures 97.3 mm.

For perspective, version 2 was 91.1 mm and version 3 reached 94.6 mm. That said, this already feels like enough, and possibly even a bit too much. We hope Saucony keeps future versions similar, as adding more width would be unnecessary for a shoe that is already very stable.

The upper includes plenty of TPU reinforcements for a rugged build, but we wanted to see how the engineered mesh of the ripstop upper handled our Dremel test.

The result was solid, earning a 3/5, although it’s far from the strongest performance we’ve seen.

On the flip side, the heel padding performed poorly and scored only 1/5, the lowest possible rating. This should be a concern (or even a deal-breaker) for runners who often wear holes in this area.

The new Vibram rubber grips like Super Glue, but does it last?

To check, we pushed the Dremel to 10K RPM with the same 2N of force. The result was solid, with 1.0 mm of rubber removed, suggesting a dependable lifespan.

This is the first Xodus Ultra without a rock plate, and that can be an issue on rocky terrain where sharp stones or debris can be felt through the sole. To compensate for the missing plate and protect your feet, Saucony added a thick 2.1 mm layer of rubber.

Here comes one of the most interesting parts, as the Xodus Ultra 4 includes an insole that avoids cheap EVA foam. Instead, it uses a 6.0-mm, TPU-based PWRRUN+ insert that brings some extra energy return and improved shock absorption to the shoe.

We’ve been asking for years why other brands don’t take this approach, as they innovate heavily in the midsole but still rely on basic EVA insoles. Yet many years later, Saucony remains the only major brand—aside from a few smaller players—that includes a premium insole.

If you don’t like the PWRRUN+ insole or want a bit more room in the toebox, you can swap in a thinner option and use this one in another shoe to boost energy return. For example, adding it to a Nike Vomero Premium gives you even more shock absorption... for free!

We put the XU4 in the freezer for 20 minutes and checked the PWRRUN PB foam again. It became 27% firmer, which was a bit worse than we expected.

We hoped version 3 would bring an upgrade here and expected reflective elements in version 4, but it looks like we’ll have to wait a bit longer.

The lacing system gets a clear upgrade, now using a hybrid setup that mixes punched eyelets with four extra-durable loops for smoother pressure distribution across the instep. We also appreciated the double stitching and the tongue loops that help keep everything centred during long runs.

However, the laces leave room for improvement. They don’t match a true trail aesthetic, they skip reflective details, and they slide a bit more than we wanted. Even a simple tongue loop like the one on the Brooks Caldera 8 could have helped for that.

And Saucony continues to tweak the tongue design. The XU2 had a thin 3.7 mm tongue, while the XU3 jumped to a bulky 9.8 mm. This year they trimmed it to 7.9 mm, which feels better but still heavier than ideal for this shoe. A slimmer ~5 mm option would make more sense.

We liked that the tongue is attached to the sides, which is ideal for preventing any shifting during long ultra efforts.

Like many shoes this year, the Saucony Xodus Ultra 4 comes with a small price hike from its predecessor. It's not good news, but at least it makes some sense given the added cost of the new Vibram outsole. Still, it’s clear that Saucony is passing part of that upgrade directly to the consumer, and some of you may find a bit frustrating.

We noted that the finger-loop heel tab uses double stitching for extra strength, just like the lace loops. It's also easy to grab, and helpful when slipping the shoe on quickly.