The Onyx Arête LWB MAN TGE adventure campervan at camp

Room to spread out.

The Arête is a long wheelbase adventure van built around two — the same open layout as the Summit, with more living space, a full shower room, and the option of a third berth when you want to bring someone along.

Arête · LWB MAN TGE Campervan · From £135,000 inc VAT Book your discovery call
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The Arête

The open two-berth, with more room to live in.

Some couples drive away from the Summit wishing they could have all of it on a slightly bigger footprint — the same open feel, the same uncomplicated way of living in the van, but with more floor to move around in and a permanent bathroom.

The Arête is that van. It takes the layout that makes the Summit work — the driver’s-side kitchen, the open living area — and turns the extra length of a long wheelbase MAN TGE into a permanent shower room and the option of a third berth, without ever closing the van in. The result is more space at every point of the day: more room to sit, more floor to move around in, and a bathroom that doesn’t fold away because it doesn’t need to.

It’s built around two people first. When you want to bring a third — a grandchild for the summer, a friend for a long weekend, a parent joining a trip — an optional third belted seat carries them on the road and the optional pop-top gives them a proper berth at night. The rest of the time, the van stays open and roomy, set up for the two of you.

The Arête sits at the top of our standard range — the most space and the highest specification we build before a project becomes bespoke.

Designed and built in our West Sussex workshop

Open living area of the Onyx Arête long wheelbase campervan

Built around two, with room for a third.

Where the Arête started

It began as a one-off commission

The Arête began as a one-off commission. A buyer came to us wanting the open, uncomplicated feel of the Summit on a longer van — more room to live in, a full permanent shower room rather than a fold-away cubicle, and the option to bring an occasional third person along. It was a clear brief, and the van we built around it worked well enough to become a model.

At a glance

The Arête at a glance

Built around two, open and roomy, with a third berth on demand. Full shower room as standard. Available in FWD and 4×4.

King-sized lengthways bed

Sliding bed — slide it back to open up the seating, or leave it out all day.

Permanent shower room

Full enclosed shower and toilet — no setup required.

Third berth on demand

Both optional — the pop-top adds an upper berth, and a fold-away belted seat carries a third on the road.

Full kitchen

Double induction hob, 75L fridge, stainless sink.

Off-grid as standard

Victron 400Ah lithium, 3kVA inverter and gas-free Truma diesel heating — days off-grid, no hookup needed.

Rear garage

Open-through, L-track throughout.

Available in 4×4

MAN TGE platform — FWD or 4×4.

Customise your colours

Cabinetry, fabrics, worktop and more — yours to choose, included as standard. Jump to the picker →

Inside the Arête

The interior, feature by feature

Tap or hover any feature to read more. The exterior is further down the page.

Open long-wheelbase living area in the Onyx Arête

The space

Everything that makes the Summit feel so much larger than its size — the open living area, the uncluttered sightlines — on a long wheelbase. The extra length goes where it’s most useful: more space to sit and relax, and a permanent shower room that doesn’t have to be borrowed from anywhere. For couples who want to live in the van rather than camp in it, the difference is felt every day.

Permanent enclosed shower room in the Onyx Arête

The shower room

Permanent and fully enclosed, built to the same standard as the rest of the van — aluminium powder-coated walls, a stainless steel tap and mixer, and a removable composting toilet. It’s there the moment you want it, with no setup and nothing to put away afterwards. When it’s not in use, L-track inside means it doubles as secure storage.

Optional third belted seat in the Onyx Arête

Room for a third

Set up for two as standard, with a king-sized lengthways sliding bed. Two optional extras bring a third along when you want one: a belted travelling seat, which folds away when it isn’t in use, and the Onyx pop-top, which adds a comfortable upper berth at night. Neither is fitted as standard, and neither closes the layout down — the rest of the time the van stays an open two-berth.

Cooking on the double induction hob in the Onyx Arête kitchen

The kitchen

A double induction hob, a 75L Dometic compressor fridge and a stainless sink and tap — a full galley for people who cook properly rather than just boil water. It is the same kitchen we fit to the Summit, with the long wheelbase giving you room to prepare without working around yourself. A Dometic three-in-one microwave, convection oven and grill is available as an upgrade.

Victron touchscreen and 400Ah lithium system with diesel heating in the Onyx Arête

Off-grid set up

A full Victron system — two 200Ah LiFePO4 batteries giving 400Ah, roof-mounted solar via an MPPT controller, a 3kVA inverter with mains charging, and a DC/DC charger that tops the batteries up from the engine as you drive. Heat and hot water come from a Truma Combi 6D diesel system that runs off the main fuel tank, so there’s no gas cylinder to manage and warming the van in the cold doesn’t eat into your electrical reserves. For deep winter, the Aquahot hydronic upgrade adds two-zone control and underfloor heating. It’s all managed from one touchscreen; most owners stop checking it within a week.

The king-sized lengthways bed in the Onyx Arête, seen past the permanent shower room with the rear doors open

King-sized bed

A king-sized bed running lengthways down the van, so there’s no climbing over anyone to get out in the night. It slides back to open up the seating area when you want the space. The difference the long wheelbase makes is that you don’t have to: leave the bed out all day and there’s still room to cook, sit and move around it.

Open-through rear garage of the Onyx Arête seen from the rear doors

The garage

The rear garage is open-through, so length isn’t the limiting factor it can be on other campervans. Bikes, boards, bags and cases all go in without a fight, and L-track is fitted throughout for securing a load properly on the drive. A slide-out gear tray is available as an option.

Overhead storage shelf with packing cubes and LED lighting in the Onyx Arête

Storage

There is more storage here than the open layout lets on. Deep drawers run under the seating, and aluminium overheads designed around packing cubes have bungee retainers so nothing moves on the road. Everything you reach for stays organised and within arm’s length rather than buried in the garage, and the light finish keeps the van feeling open rather than boxed in. The air conditioning unit shown is an option, not standard.

The layout

How the Arête is laid out

An open and spacious two-berth, with an optional third berth available.

Onyx Arête floor plan — day layout, driver's-side kitchen, open living space and permanent shower room
Onyx Arête floor plan — lounge layout, the seating extended across the living space
Onyx Arête floor plan — night layout, the king-sized lengthways bed made up
Onyx Arête MAN TGE with roof rack and all-terrain tyres in woodland
Outside the Arête

Built for where you’re going

Designed and fabricated in-house — not bought off a shelf. Every component is chosen to be useful on the road, not just to look the part in a photograph.

An Onyx roof rack, fitted as standard

Every Arête leaves the workshop with an Onyx aluminium roof rack — designed by us, fabricated by us, and fitted as standard. It’s sized to carry rooftop kit properly, with a side ladder for safe, clean access. The pop-top, when fitted, is designed to keep the rack fully usable when it’s closed.

Options that suit longer trips

Many buyers add optional upgrades before their first trip: Black Rhino Warlord alloys, Onyx rear carriers with wheel carrier, and a Fiamma F45 awning. None are included in the standard price, but all are available — and for buyers heading off-road or spending extended time away from facilities, they make a real difference.

Specification

Every Arête, built to this standard

Options and upgrades are listed separately below.

Base vehicle

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ModelMAN TGE 4.160 LWB — 8-speed automatic
DrivetrainFront-wheel drive as standard — 4×4 available
Gross weight4,000kg
TrimLion XC
SuspensionUpgraded suspension
HeadlightsLED
Cab seatsFactory swivel seats
Cab air conditioningFitted as standard (habitation air con is a separate option)
Driver aidsCruise control, rear view camera
InfotainmentTouchscreen with Apple CarPlay and Android Auto
ExteriorMud flaps

Dimensions

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Berths2 standard, 3 with pop-top
Travelling seats2 standard (optional third belted seat, folds away when not in use)
Bed dimensionsKing-sized lengthways — 1,990 × 1,680mm

Electrical

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SystemVictron — 12v
Batteries2× 200Ah Victron LiFePO4 (400Ah total)
Solar400W roof-mounted, Victron MPPT controller (350W if pop-top fitted; 480W high-efficiency upgrade available)
InverterVictron 3kVA
Mains charging120A via inverter/charger
DC/DC chargerVictron 50A
Shore powerHook-up compatible as standard
MonitoringVictron touchscreen

Water & Heating

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Heating systemTruma Combi 6D diesel
Fuel sourceMain diesel tank — no separate gas cylinder
Hot waterOn demand (no cylinder)
Fresh water109 litres
Grey water87 litres (4×4) / 63 litres (FWD)
VentilationMaxxair Maxxfan
Underfloor heatingOptional upgrade (requires Aquahot)

Kitchen

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HobDouble induction
Microwave/ovenOptional upgrade — Dometic three-in-one (microwave, convection oven, grill)
FridgeDometic NRX80 compressor fridge
SinkStainless steel with tap
WorktopHi-Macs composite

Living

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Shower roomPermanent enclosed shower and toilet — aluminium powder-coated, stainless tap and mixer
ToiletRemovable composting toilet — Clesana X1 Pro heat-sealing toilet available as an upgrade
Shower room storageL-track fitted inside — doubles as storage when not in use
BedKing-sized lengthways sliding bed
Pop-topOptional — Onyx-designed, adds an upper berth, integrated lighting, clamshell close, solar-ready
SeatingOpen lounge; optional third belted seat, folds away when not in use
StorageDeep drawers under the seating; aluminium overheads with bungee retainers
FurnitureHPL throughout — choice of colours, powder-coated aluminium corners
Garage tie-downL-track throughout

Exterior & Chassis

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Roof rackOnyx aluminium — designed and fabricated in-house
Side ladderFitted as standard
Side stepBlack step fitted as standard
Rear stepBlack step fitted as standard

Full base vehicle specification available on request. Options are available to change the specification — call us to discuss.

A couple relaxing at the open side door of the Onyx Arête campervan
Investment

From £135,000 inc VAT

The Arête starts from £135,000 inc VAT, depending on specification and base vehicle.

It is our most spacious two-berth — a long wheelbase van built around two people, with a full shower room and the option of a third berth. That price includes everything in the spec table above, with no stripped-back entry specification designed to get you in the door.

We’re happy to talk through what’s included, what’s optional, and what the total cost of your build would look like on a discovery call.

Book your discovery call →
Customise

Customise your build

The Arête is complete as standard. The options below are for buyers who want a third berth, more capability, or a more specific fit for their trips. We’ll talk through what makes sense on your discovery call.

Start with

Tick the upgrades below to build your spec — it’s an estimate, not a quote.

Third berth & sleeping

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The Arête is a two-berth as standard, with a king-sized lengthways bed. The optional pop-top adds a comfortable upper berth, and an optional third belted seat, which folds away when it is not in use, carries a third person on the road.

Onyx pop-top — adds the third upper berth, integrated lighting, clamshell close, solar-ready. Includes the swap to a 350W solar panel, wiring up to the pop-top with reading light and storage boxes, and the Maxxfan relocated to the pop-top£5,800
Third belted travelling seat — folds away when not in use£2,500
Upgraded mattress — memory foam£600
Upgraded mattress — pocket sprung£1,000

Climate

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The Arête is fitted with the Truma Combi 6D diesel system as standard. The Aquahot hydronic upgrade adds continuous hot water, two-zone control and underfloor capability; underfloor heating requires the Aquahot upgrade (added automatically). Habitation air conditioning is one option at one price: limited off-grid use on a 12v system, or full off-grid use on a 24v system. If you plan to run it off-grid we’d recommend adding a battery and the 24v upgrade alongside it — both are in Electrical systems below.

Aquahot hydronic diesel heating — continuous hot water, two-zone control, underfloor capability£4,000
Underfloor heating — third hydronic zone (requires Aquahot)£4,500
Habitation air con£5,000

Electrical systems

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Additional 200Ah Victron LiFePO4 smart battery£1,050
DC/DC charger upgrade — 100A (replaces standard 50A, requires upgraded alternator)£800
24v system — 5kVA inverter and 3×100Ah batteries£2,700
Additional solarPOA
Upgraded USB — Tiger Exped high-powered USB A/C (replacement)£100
Additional Tiger Exped high-powered USB A/C£180
Additional Scanstrut USB A/C port£150
Additional 240v sockets — up to two extra, four in total£200 each
Starlink Roam — fitting only£500

Internal additions

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Clesana X1 Pro heat-sealing toilet (replaces the composting toilet)£800
Dedicated socket for the Clesana X1 Pro (otherwise it runs on battery power)£200
Dometic three-in-one — microwave, convection oven, grill (installed)£500
Sink chopping board infill£100
Garage slide-out gear tray£750
Ridgeline bug screen — side door, including fitting£400
Ridgeline insulated bug screen and blind — rear, including fitting£620
Seat upholstery — front seatsfrom £2,000
Seat upholstery — rear seat (with the third belted seat)from £1,000 each

External upgrades

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Onyx rear carriers and wheel carrier£2,000
Storage boxes for rear carriersPOA
Tokul bike rack — suitable for all bikes, including fitting£550 each
Fiamma F45 awning£1,000
External spotlightsfrom £250
Black Rhino Warlord alloys — four, or five with the spare£400 each
Underbody protectionPOA
ARB air compressorfrom £500

Base vehicle factory upgrades

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Non-standard colour£1,439
Tow bar£796
Heated and folding electric mirrors£192
Heated windscreen£341
Heated steering wheel£110
Cruise Assist (adaptive cruise control)£1,328
Leatherette seat covering£79
Upgraded alternator (enables future DC/DC charger upgrade)£432
Manual diff lock (AWD only)£680
Seikel 35mm lift kit£5,606
0 items selected £135,000 inc VAT

An indicative estimate based on list options — not a formal quote. The base vehicle, factory choices and any POA items are confirmed on your discovery call.

Take this spec to a discovery call →

Make it yours

Choose your colours and finishes

Every Arête is finished to your taste. Pick the cabinetry, doors, flooring, worktop, wall lining and seating that feel like you – your palette builds as you go, and it’s included as standard.

Included as standard, on every Arête

Your palette

Build your palette freely – we just ask for an email when you download.

Who it’s for

Two people who sometimes need a third berth

Grandparents are a good example — travelling as a couple most of the time, with a grandchild along for part of the holidays.

The Arête is built for people who…

  • Travel mostly as two and want the most open, comfortable two-berth we build
  • Want more living space than the Summit and a permanent shower room
  • Occasionally bring a third person — a grandchild, a friend, a parent — and want them carried and slept properly when they come
  • Spend longer periods living in the van rather than camping out of it
  • Want a long wheelbase and a full shower room without moving to a bespoke build

Whether it’s a month touring the west coast of Scotland or a season working through Europe, the Arête is the van with room to do it in comfort.

FAQ

Questions worth asking

How is the Arête different from the Summit?

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Both share the same open layout and the same way of living in the van. The Summit is the medium wheelbase version — more agile, easier to park, and the right choice if a compact footprint matters to you. The Arête takes that layout onto a long wheelbase, which gives you more living space, a permanent shower room rather than a fold-away cubicle, and the option of a third berth. If you love the Summit but want more room, the Arête is the answer.

How is the Arête different from the Mesa?

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The Arête is built around two people, with the option of an occasional third. The Mesa is built around four — four permanent belted seats, a layout designed for a family, and a different kitchen arrangement to suit it. If your travelling is mostly two of you with the occasional extra, the Arête keeps the van open and roomy for the two of you. If you regularly carry and sleep a family of four, the Mesa is built for that from the ground up.

What are my shower and toilet options on the Arête?

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The Arête has a permanent dedicated shower room — a full fixed enclosure with shower and composting toilet, there whenever you want it with no setup. There’s also an outdoor shower connection at the rear for rinsing kit, wetsuits, and dogs.

How many people can the Arête sleep?

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Two as standard, on the king-sized lengthways sliding bed. The optional Onyx pop-top adds a third berth in the elevated roof section. If you want to carry a third person on the road as well, an optional third belted seat is available, and it folds away when it is not in use. Four-berth, four-seat use is the Mesa’s territory — the Arête is a two-berth that flexes to three.

What is a composting toilet and does it smell?

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A composting toilet separates liquid and solid waste, which is what prevents odour. Used correctly — and they’re simple to use — a composting toilet in a well-ventilated van is odour-free in normal use, and most owners stop thinking about it within the first week. The practical advantages over a cassette toilet are real: no chemicals, no cassette to empty at a disposal point, and no dependency on campsites.

What off-grid capability does the Arête have?

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The Arête runs a full Victron off-grid electrical system with 400Ah of LiFePO4 lithium capacity, roof-mounted solar, and diesel heating that runs from the main fuel tank rather than the battery. In practical terms that’s several days of comfortable use without solar input, and indefinitely with reasonable sun. Additional battery capacity and solar are available for extended trips.

Can I use the Arête in winter?

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Yes — it’s built for year-round use across the UK and Europe. The van is insulated throughout, the water tanks are insulated and heated, and the diesel heating runs from the main fuel tank with no gas cylinder to run out of on a cold night.

Do I need a special licence to drive the Arête?

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Yes. The Arête is built on a 4,000kg gross weight base vehicle as standard, which puts it above the 3,500kg limit covered by a standard Category B car licence. Driving it needs C1 entitlement, which covers vehicles between 3,500kg and 7,500kg.

If you passed your car test before 1 January 1997, you will almost certainly have C1 already — it is listed in the categories on the back of your photocard, and it is worth checking there before anything else. If you passed after that date, C1 is a separate entitlement: a medical, a theory test and a practical test, usually completed over a few days.

We would rather you knew this at the enquiry stage than at handover. The base vehicle specification can be changed, so if C1 is a problem, raise it on your discovery call and we will work through the options and what each one means for payload. C1 entitlement on a UK licence is recognised across the EU.

Why the MAN TGE over the VW Crafter or Mercedes Sprinter?

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The MAN TGE isn’t the most familiar choice — most people arrive expecting a Sprinter — but it’s the right platform for what we build, and the reasons are practical.

Against the Sprinter, it’s comparable in quality and capability at a slightly lower base price, which means more of your budget goes into the build rather than the base vehicle.

Against the VW Crafter, the more important difference is support. The MAN TGE is the commercial vehicle version of the same platform, which means it’s backed by MAN’s truck dealer network — service centres across the UK and throughout Europe. For a van you’re taking seriously into remote places, that network matters in a way it doesn’t for a van that stays close to home.

We’ve driven other platforms. We kept coming back to this one.

What warranty do I get with the Arête?

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The MAN TGE base vehicle comes with a three-year manufacturer warranty through the MAN dealer network across the UK and Europe. The Onyx build is covered by a one-year Onyx warranty, and Victron components carry their own manufacturer warranty. Every completed build also comes with a free three-month check-up.

Is the Arête road legal?

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Yes. Every Arête goes through an Individual Vehicle Approval process and is registered from new as a motorhome. A panel van registration option is available if preferred and comes with a small discount on the build price. It’s worth understanding the insurance and usage implications of each before you decide.

The rest of the range

Not sure the Arête is the one?

If you want the same open layout in a more compact, easier-to-drive van, the Summit is the medium wheelbase version. If you need to carry and sleep a family of four, the Mesa is built around exactly that. And if neither quite fits, Hors Catégorie is our bespoke build programme.

Compare all models →

Get in touch

Ready to talk?

A discovery call is a relaxed 30-minute conversation about your trips, the way you travel, and whether the Arête is the right van for you. Just an honest conversation with the people who’ll build it.

We typically have a four-to-six month lead time, so the sooner you get in touch, the sooner we can get your build in the diary.

Book your discovery call → Or call us on 01403 458 668

Not ready to talk yet?Join the list for new models, open build slots and workshop updates.

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