Head to head
Equi-Trek Sonic Five Seats 3,500kg vs Ifor Williams Business Inabox
The Ifor Williams Business Inabox is 600kg lighter empty.
Last reviewed 13 September 2026
Key differences
- Unladen weight: the Equi-Trek Sonic Five Seats 3,500kg weighs 600kg more empty.
Specifications side by side
| Equi-Trek Sonic Five Seats 3,500kg | Ifor Williams Business Inabox | |
|---|---|---|
| Gross weight | 3500kg | 3500kg |
| Unladen weight | 2500kg | 1900kg (Workshop M) |
| Internal length | - | 4.45m (Workshop M) |
| Internal width | - | 2.18m |
| Overall length | - | 5.96m (Workshop M) |
Sources: Equi-Trek Sonic Five Seats 3,500kg, Ifor Williams Business Inabox. 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.
Listed by
- Trek-Trailers Lincolnshire - Doncaster, Belton
- Trek-Trailers Three Counties - Hereford
Buy or hire the Business Inabox if...
- you want one that is 600kg lighter empty
A trailer shell fitted out as a mobile workshop, shop or catering unit rather than a load carrier. Tradespeople and mobile caterers buy it to take a fitted-out workspace to a site rather than build one into a van.
Listed by
- Norfolk Trailers - Norwich
Common questions
What is the difference between the Equi-Trek Sonic Five Seats 3,500kg and the Ifor Williams Business Inabox?
The Ifor Williams Business Inabox is 600kg lighter empty. The Equi-Trek Sonic Five Seats 3,500kg is a 5-seat version of the Sonic motorised horsebox; the Ifor Williams Business Inabox is a trailer-based mobile workshop, boxvan or catering/retail unit.
Which is lighter, the Equi-Trek Sonic Five Seats 3,500kg or the Ifor Williams Business Inabox?
The Ifor Williams Business Inabox. It is 600kg 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 Business Inabox 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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