Asics Magic Speed 4 vs Asics Magic Speed 5:
Which to Choose

The headline change is that the Magic Speed 5 got leaner and faster. It weighs 201g in a men's US 9, roughly 40g lighter than the Magic Speed 4's ~242g, and it sits lower underfoot — about a 35mm heel and 27mm forefoot versus the 4's taller ~39mm heel — so the ride feels more direct and ground-connected instead of cushioned. That shift shows up in the scores and the intended distances: cushioning drops from 5/6 on the 4 to 4/6 on the 5, and the wheelhouse moves down from 10K/half/marathon (with the half as the 4's sweet spot) to 5K/10K/half (with the 10K as the 5's sweet spot). The foam and plate philosophy changed too. The Magic Speed 4 runs FF Blast Plus Eco over a full-length carbon plate for a springy, moderately firm roll that comes alive at pace; the Magic Speed 5 layers livelier FF Leap over an FF Blast+ base and pairs it with a partial, forefoot-forked carbon plate, which snaps you forward hard when you're rolling but offers a bit less of the long, smooth, protected propulsion the 4's full plate and taller stack give over marathon distance. Both are neutral with a moderately planted (not ultra-wide) base, and both go stiff and a little flat at jogging pace — neither wants to go slow. Drop is nearly identical: 7mm on the 4, 8mm on the 5. And because both use an EVA-based foam rather than a PEBA superfoam, neither matches Asics' top racers for outright energy return; the 5 simply trades some of the 4's cushion and marathon composure for lower weight and quicker turnover.