Head to head
Equi-Trek Sonic Five Seats 3,500kg vs Ifor Williams HB511
The Ifor Williams HB511 is 1.5 tonnes lighter empty. The Equi-Trek Sonic Five Seats 3,500kg is rated 800kg heavier gross.
Last reviewed 13 September 2026
Key differences
- Unladen weight: the Equi-Trek Sonic Five Seats 3,500kg weighs 1.5 tonnes more empty.
- Gross weight: the Equi-Trek Sonic Five Seats 3,500kg is rated 800kg heavier gross.
Specifications side by side
| Equi-Trek Sonic Five Seats 3,500kg | Ifor Williams HB511 | |
|---|---|---|
| Gross weight | 3500kg | 2,700kg |
| Unladen weight | 2500kg | 1,000kg |
| Internal length | - | 3.52m |
| Internal width | - | 1.79m |
| Brakes | - | Braked |
Sources: Equi-Trek Sonic Five Seats 3,500kg, Ifor Williams HB511. 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...
- you want one that is rated 800kg heavier gross
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 HB511 if...
- you want one that is 1.5 tonnes lighter empty
The wider step up from the HB506, for larger horses or owners who want more room in transit. The extra 12cm of internal width and 36cm of length cost 80kg unladen, which is worth checking against your tow vehicle before choosing it over the HB506.
Listed by
- Trek-Trailers Lincolnshire - Doncaster, Belton
- Trek-Trailers Suffolk - Bury Saint Edmunds
- R M Trailer Centre - Middlesbrough, North Ormesby
- Blains Trailers & Tyres - Hemel Hempstead, Great Gaddesden
- Horse Trailer Sales - Robertsbridge, Staplecross
- Trek-Trailers Three Counties - Hereford
Common questions
What is the difference between the Equi-Trek Sonic Five Seats 3,500kg and the Ifor Williams HB511?
The Ifor Williams HB511 is 1.5 tonnes lighter empty. The Equi-Trek Sonic Five Seats 3,500kg is rated 800kg heavier gross. The Equi-Trek Sonic Five Seats 3,500kg is a 5-seat version of the Sonic motorised horsebox; the Ifor Williams HB511 is a two-horse trailer, twin axle, wider body.
Which is lighter, the Equi-Trek Sonic Five Seats 3,500kg or the Ifor Williams HB511?
The Ifor Williams HB511. It is 1.5 tonnes 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 HB511 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.
GetBrent is an independent directory and is not a dealer for, nor affiliated with, either manufacturer. Model and brand names are the trademarks of their owners.