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40Race Shoe FinderEst. 2023 · London

Head to head

adidas Prime X 3 Strungvs
New Balance FuelCell SuperComp Trainer v4

Prime X 3 Strung

£149

Typical street price · £250 RRP

■ 50mm — over limit
FuelCell SuperComp Trainer v4

£157

Typical street price · £190 RRP

■ 47mm — over limit

Choose the Prime X 3 Strung if…

  • You want the bigger return: 3–4.2% economy gain against 2.4–3.5%, and that gap widens the longer you are out there.
  • You want a conventional fit rather than a narrow or wide last.

Choose the FuelCell SuperComp Trainer v4 if…

  • You have a broad foot, or your toes spread as a long race goes on.
  • You want more races out of one pair: about 650km of competitive life against 500km.

What does this
mean for you?

Every figure below is recalculated from your race and your current time. The gap between two shoes is not fixed — it grows with how long you are on your feet.

Over marathon from 3:45:00

Time back
Prime X 3 Strung: 152s–233sFuelCell SuperComp Trainer v4: 111s–186s
Cost per second saved
Prime X 3 Strung: £0.10FuelCell SuperComp Trainer v4: £0.10

Ranges, not promises. Both figures are against a standard trainer, and the honest answer for most runners is that the difference between two shoes of this class is smaller than the difference a month of decent training makes.

Every number.

010203040505044
Prime X 3 Strung
010203040504741
FuelCell SuperComp Trainer v4

What you pay

Street price
Prime X 3 Strung£149■
FuelCell SuperComp Trainer v4£157

What the shoe is actually selling for across the shops we read, not its RRP.

RRP
Prime X 3 Strung£250
FuelCell SuperComp Trainer v4£190

List price. Almost nobody pays it for a race shoe.

Cost per race
Prime X 3 Strung£19
FuelCell SuperComp Trainer v4£15■

Street price divided by the races the foam stays fast for.

Cost per second saved
Prime X 3 Strung£0.10■
FuelCell SuperComp Trainer v4£0.10

The whole-life question: what each second of race time costs you.

What it does

Estimated saving
Prime X 3 Strung152s–233s■
FuelCell SuperComp Trainer v4111s–186s

Against a standard trainer, over the distance and time set above.

Economy gain
Prime X 3 Strung3–4.2%■
FuelCell SuperComp Trainer v42.4–3.5%
Built for
Prime X 3 StrungMarathon · Ultra
FuelCell SuperComp Trainer v4Marathon · Ultra
Best use case
Prime X 3 StrungDeliberately built past the rules. Enormous stack, huge cushioning, and superb for long training runs or any race that does not apply World Athletics regulations.
FuelCell SuperComp Trainer v4A max-stack plated trainer that makes easy miles feel effortless. Beloved for long runs.

How it is built

Weight
Prime X 3 Strung275 g
FuelCell SuperComp Trainer v4269 g■

Manufacturer figure at men's US 9.

Stack (heel)
Prime X 3 Strung50 mm
FuelCell SuperComp Trainer v447 mm
Stack (forefoot)
Prime X 3 Strung44 mm
FuelCell SuperComp Trainer v441 mm
Drop
Prime X 3 Strung6 mm
FuelCell SuperComp Trainer v46 mm
Foam
Prime X 3 StrungLightstrike Pro
FuelCell SuperComp Trainer v4PEBA FuelCell
Plate
Prime X 3 Strungcarbon fibre
FuelCell SuperComp Trainer v4carbon fibre

Rules and fit

Road legal
Prime X 3 StrungNo (50 mm)
FuelCell SuperComp Trainer v4No (47 mm)

World Athletics caps road racing shoes at 40 mm of stack.

Fit
Prime X 3 Strungstandard
FuelCell SuperComp Trainer v4wide
Stability
Prime X 3 Strungbalanced
FuelCell SuperComp Trainer v4balanced

Neither is better in the abstract — it depends on your stride.

Race life
Prime X 3 Strung~500 km
FuelCell SuperComp Trainer v4~650 km■

How long the foam stays fast, not how long the shoe survives.

Data confidence
Prime X 3 Strungverified
FuelCell SuperComp Trainer v4verified

■ marks the better figure where one is genuinely better. Fit, foam, drop and stability carry no mark — they depend on your foot and your stride, not on which shoe is superior.

In your size.

Where to buy

Your UK size

Best price today — some sizes£145at Runningbear — £105 under RRP

9 retailer checks failed on the last run, so their prices are missing rather than wrong.

Prices are captured when the site is built and stamped with the time of that check. We never rank a retailer by what it pays us; where a link earns a commission it is marked sponsored and the price you pay is unchanged.

Where to buy

Your UK size

Best price today — some sizes£157at Amphibianking — £33 under RRP

9 retailer checks failed on the last run, so their prices are missing rather than wrong.

Prices are captured when the site is built and stamped with the time of that check. We never rank a retailer by what it pays us; where a link earns a commission it is marked sponsored and the price you pay is unchanged.