If your Saucony Endorphin Speed 5 still feels comfortable and responsive, does the Speed 6 offer enough to justify replacing it? The useful distinction is how you train: dedicated tempo sessions place different demands on a shoe from easy mileage and occasional faster efforts.
The supplied reviews describe the Saucony Endorphin Speed 6 as a livelier, more assertive update, with new PWRRUN PBX foam, additional cushioning depth, and revised plate and rocker geometry. The Saucony Endorphin Speed 5 remains a credible option for runners who value a more grounded, adaptable ride.
This comparison synthesises the supplied research; Verdosa has not personally tested either shoe.
What the research does and does not establish
The summaries broadly agree on the foam change and an increase from 36/28 mm to 38/30 mm in stated stack height. However, Speed 6 prices vary, reported weights differ, and testers disagree about stiffness, toe room, and long-run protection. The comparisons below retain those distinctions rather than presenting every review as unanimous.
Ride: a stronger reason to upgrade than weight
The Speed 5 combines PWRRUN PB foam, a nylon plate, and SPEEDROLL geometry. The Run Testers describe a smooth transition across different paces; Doctors of Running also report comfortable easy running and consistent cushioning beyond ten miles.
The Speed 6 changes the experience through PWRRUN PBX foam and revised geometry. Alastair Running describes an earlier roll onto the forefoot and sharper toe-off, while Doctors of Running finds a particularly snappy response once the pace rises.
For sustained tempo work, that gives the Speed 6 a clearer purpose: it suits runners who want their workout pair to feel distinctly different from an easy-day trainer. It does not establish a measurable improvement in race times.
Reported weights generally favour the Speed 6, but inconsistent Speed 5 baselines prevent a clean, universal gram-saving claim. Treat the changed ride as the main upgrade, with lower reported weight a secondary benefit.
Everyday training: versatility has a trade-off
For a runner buying one pair, the Speed 5 has a persuasive case. Its less insistent ride makes it easier to accommodate warm-ups, steady mileage, and faster sections without building an entire session around the shoe.
That recommendation is an interpretation of the review pattern, not a guarantee that everyone will find it softer. Some Speed 5 reviewers wanted more cushioning, and some Speed 6 testers enjoyed ordinary daily runs.
The Speed 6 is the more uncertain choice for recovery-heavy training. Believe in the Run praises its versatility, but Matt Klein’s Doctors of Running video describes harsh initial easy miles and a break-in period of roughly 20–30 miles. Buyers seeking immediate comfort at slow speeds should weigh that disagreement carefully.
Long runs and a first marathon
The extra 2 mm of stated forefoot stack gives the Speed 6 more material underfoot, but does not prove it will feel more protective to every runner. RoadTrailRun welcomes the additional protection; TF XC’s supplied review finds forefoot cushioning insufficient for longer efforts.
The Speed 5 produces a similar split. Doctors of Running reports maintained cushioning on longer runs, whereas The Run Testers includes a reviewer who wanted more forefoot protection.
For a first marathon, neither model earns an unconditional recommendation. Choose the Speed 5 if it already stays comfortable during your longest training runs. Consider the Speed 6 if you prefer its faster rolling transition and confirm that the upper and forefoot remain comfortable over distance.
Neither shoe needs to be replaced simply because it lacks a carbon plate. Both offer training and racing applications in the supplied reviews; suitability depends on your response to the complete shoe.
Fit: more room does not remove toe pressure
The Speed 5 sizing reports range from true to size to slightly short. Runner’s World UK recommends extra length for its tester, while all four Run Testers reviewers stayed in their usual size.
The Speed 6 does not settle that question. Runner’s World reports a roomier midfoot and forefoot, but Doctors of Running and TF XC still identify taper or toe-guard pressure. Additional volume across the foot does not necessarily mean more usable space at the longest toe.
Use your successful Speed 5 size as a starting point, then check toe clearance and heel security in the Speed 6. Avoid an automatic half-size increase based solely on the model change.
Both have breathable mesh, but the Speed 6 research includes reports of abrasive material and long-run hot spots. Runners sensitive to upper friction should make comfort with running socks part of the purchase decision.
Grip and durability: no proven longevity winner
The supplied reviews support road use for both shoes, including positive wet-pavement experiences. They do not provide a matched traction test establishing that the Speed 6 grips better.
Durability is similarly unresolved. Speed 5 testing identifies exposed-foam wear, while several Speed 6 reviewers question limited heel rubber coverage. Later Doctors of Running video testing reports only slight rubber wear after 100 km, illustrating why early concerns should not become a fixed lifespan prediction.
For runners who wear through the heel quickly, the Speed 6 outsole deserves inspection before buying. Neither research file supports a guaranteed mileage figure or a confident cost-per-mile comparison.
Price: compare the actual offer
The Speed 5 research lists US$175 and £180. Speed 6 sources differ between US$175 and approximately US$180, with an October 15, 2026 release date reported by RoadTrailRun and Believe in the Run. These are research-reported prices, not verified current offers.
A substantial Speed 5 discount strengthens its value case. At similar prices, the Speed 6 becomes more appealing for workout-focused buyers, provided its fit and ride suit them. No verified discount or current stock position was supplied.
Saucony Endorphin Speed 6
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Saucony Endorphin Speed 5
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Final Verdict
Keep the Saucony Endorphin Speed 5 if it still meets your training needs. Choose a discounted Saucony Endorphin Speed 5 for mixed training when value and a more grounded ride matter most.
Choose the Saucony Endorphin Speed 6 when replacing a worn pair or seeking a livelier tempo companion. Its strongest upgrade case is faster training, rather than a promise of greater comfort everywhere.
For first-marathon runners, wide-footed buyers, and heel-heavy wearers, make the decision conditional on long-run comfort, toe clearance, and outsole suitability. The research supports different buyer choices, not one universal winner.
FAQ
Is the Saucony Endorphin Speed 6 worth upgrading to from the Speed 5?
Yes, conditionally: the Saucony Endorphin Speed 6 has a stronger case for runners seeking a livelier workout ride or replacing a worn pair. The research does not establish that upgrading a comfortable, serviceable Saucony Endorphin Speed 5 will improve every run.
What are the main differences between the Saucony Endorphin Speed 6 and Speed 5?
The main changes reported are PWRRUN PBX replacing PWRRUN PB, stated stack increasing from 36/28 mm to 38/30 mm, and redesigned nylon plate and SPEEDROLL geometry. Both retain an 8 mm stated drop. Reviewers generally describe the Speed 6 as snappier, although comfort and stiffness assessments differ.
Does either shoe have a carbon plate?
No. Both the Saucony Endorphin Speed 6 and Saucony Endorphin Speed 5 use nylon plates. Nylon construction alone does not guarantee a flexible-feeling shoe: some Speed 6 testers describe considerable forefoot stiffness.
Which is better for everyday running?
The Saucony Endorphin Speed 5 is the more conservative recommendation for runners mixing easy mileage and workouts. Some reviewers also enjoy the Saucony Endorphin Speed 6 for daily training, but others find its ride harsh or awkward at slower paces.
Which is better for a first marathon?
The research does not establish a universal winner. Both receive positive distance-running feedback, alongside cushioning reservations. For a first marathon, choose the model that remains comfortable during long training runs rather than assuming the Speed 6’s extra stack guarantees better protection.
Is the Saucony Endorphin Speed 6 wider than the Speed 5?
Some supplied reviews report a roomier Speed 6 midfoot and forefoot. Others still identify a tapered toe box or toe-guard pressure. That supports trying it for additional room, but does not establish that it will accommodate every wide foot.
Should I buy the same size in both models?
Your successful Saucony Endorphin Speed 5 size is a reasonable starting point for the Saucony Endorphin Speed 6. Both models have mixed sizing reports, so check length, toe clearance, and heel hold rather than automatically sizing up or down.
Which shoe lasts longer?
The supplied research cannot establish that. Speed 5 reviews document exposed-foam wear; Speed 6 reviews raise heel-rubber concerns but report differing early wear experiences. There is no matched long-term comparison supporting a reliable lifespan winner.