Head to head
Equi-Trek Sonic Five Seats 3,500kg vs Ifor Williams TT3621
The Ifor Williams TT3621 is 1,510kg lighter empty.
Last reviewed 13 September 2026
Key differences
- Unladen weight: the Equi-Trek Sonic Five Seats 3,500kg weighs 1,510kg more empty.
Specifications side by side
| Equi-Trek Sonic Five Seats 3,500kg | Ifor Williams TT3621 | |
|---|---|---|
| Gross weight | 3500kg | 3500kg |
| Unladen weight | 2500kg | 990kg (195/60R12C tyres) or 1000kg (185/70R13C tyres) |
| Payload | - | 2510kg (195/60R12C) or 2500kg (185/70R13C) |
| Internal length | - | 3.62m / 11'9" |
| Internal width | - | 1.95m / 6'5" |
Sources: Equi-Trek Sonic Five Seats 3,500kg, Ifor Williams TT3621. Figures vary by model year and options, so check with the supplier before you commit.
Buy or hire the Sonic Five Seats 3,500kg if...
A five-seat cab variant of the Sonic, aimed at families or small teams who want to travel together to competitions rather than sending a second car. It carries the same horse capacity as the standard Sonic.
Full Sonic Five Seats 3,500kg specifications →Buy or hire the TT3621 if...
- you want one that is 1,510kg lighter empty
The largest Ifor Williams tipper. A 3.6m by 1.95m body is chosen for bulky, lighter loads - green waste, clearance and bark - where volume runs out before weight does, and it is a staple of plant and tool hire fleets. Formerly sold as the TT126.
Full TT3621 specifications →Common questions
What is the difference between the Equi-Trek Sonic Five Seats 3,500kg and the Ifor Williams TT3621?
The Ifor Williams TT3621 is 1,510kg lighter empty. The Equi-Trek Sonic Five Seats 3,500kg is a 5-seat version of the Sonic motorised horsebox; the Ifor Williams TT3621 is a twin axle tipping trailer, 12ft body, electric tipping.
Which is lighter, the Equi-Trek Sonic Five Seats 3,500kg or the Ifor Williams TT3621?
The Ifor Williams TT3621. It is 1,510kg lighter empty than the Equi-Trek Sonic Five Seats 3,500kg.
Can I tow the Equi-Trek Sonic Five Seats 3,500kg or the Ifor Williams TT3621 on a car licence?
Yes, as far as the licence goes. Both are rated at or under 3,500kg gross, and a car (B) licence has covered towing up to 3,500kg since 16 December 2021. Your car still has to be rated to tow the loaded weight - check the handbook or the VIN plate.
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