Head to head
Ifor Williams HB403 vs Ifor Williams HB511
The Ifor Williams HB511 is rated 1.1 tonnes heavier gross and is 49cm (1.5ft) wider inside. The Ifor Williams HB403 is 233kg lighter empty.
Last reviewed 13 September 2026
Key differences
- Gross weight: the Ifor Williams HB511 is rated 1.1 tonnes heavier gross.
- Internal width: the Ifor Williams HB511 is 49cm (1.5ft) wider inside.
- Unladen weight: the Ifor Williams HB511 weighs 233kg more empty.
- Internal length: the Ifor Williams HB511 is 44cm (1.5ft) longer inside.
Specifications side by side
| Ifor Williams HB403 | Ifor Williams HB511 | |
|---|---|---|
| Gross weight | 1600kg | 2,700kg |
| Unladen weight | 767kg | 1,000kg |
| Internal length | 3.08m | 3.52m |
| Internal width | 1.30m | 1.79m |
| Payload | 833kg | - |
| Brakes | - | Braked |
Sources: Ifor Williams HB403, Ifor Williams HB511. Figures vary by model year and options, so check with the supplier before you commit.
Buy or hire the HB403 if...
- you want one that is 233kg lighter empty
The smallest trailer in the HB horsebox range, bought by owners of a single horse or a couple of ponies who want the lightest legal option that can still be towed by a mid-size car.
Listed by
- Horse Trailer Sales - Robertsbridge, Staplecross
- Barnwell Trailers Ltd - Peterborough, Oundle, Barnwell
Buy or hire the HB511 if...
- you want one that is rated 1.1 tonnes heavier gross
- you want one that is 49cm (1.5ft) wider inside
- you want one that is 44cm (1.5ft) longer inside
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 Ifor Williams HB403 and the Ifor Williams HB511?
The Ifor Williams HB511 is rated 1.1 tonnes heavier gross and is 49cm (1.5ft) wider inside. The Ifor Williams HB403 is 233kg lighter empty. The Ifor Williams HB403 is a a compact single-horse or two-pony horsebox trailer; the Ifor Williams HB511 is a two-horse trailer, twin axle, wider body.
Which is lighter, the Ifor Williams HB403 or the Ifor Williams HB511?
The Ifor Williams HB403. It is 233kg lighter empty than the Ifor Williams HB511.
Can I tow the Ifor Williams HB403 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.