Saucony Endorphin Speed 4 vs Saucony Endorphin Speed 5:
Which to Choose

Dimensionally there is almost nothing between these two. The Speed 4 sits on a 36.2mm heel / 27.5mm forefoot stack and weighs about 237g in a men's US 9; the Speed 5 measures 37mm heel / 27mm forefoot and 241g — a few grams heavier and a hair taller, differences you will not feel underfoot. Both use the same PWRRUN PB PEBA foam and a full-length semi-rigid winged nylon plate (not carbon), and both come alive only once you pick up the pace, feeling slightly floaty on easy shuffles. The meaningful change is in the plate and the ride it produces. The Speed 4's plate carries dual wings and a more pronounced rocker, giving it a snappier, more aggressive toe-off that rewards genuinely fast running; the Speed 5 revises that to a single medial wing with more torsional give, which softens the forefoot and smooths transitions but tames the rocker, so the ride feels a touch more forgiving and a touch less propulsive. That shift shows in how each is positioned: the Speed 4 is rated from the 5K up through the marathon and tuned for a 3:45–4:45 min/km window, while the Speed 5 drops the 5K and centers on 10K to marathon in a slightly more conservative 4:00–4:45 min/km zone. Both are moderate, neutral shoes with no added pronation support — the plate and contoured base steady the soft stack, but neither is a stability trainer.