BUYERS GUIDE - MOTORHOMES
Earthcruiser’s familiar motorhome module can be mounted on the back of Mercedes-Benz’ U430 Unimog.
The U430 is not the familiar Unimog shape, because the cab, with its vast windscreen, was designed primarily for use with implements, such as snow ploughs, fertiliser spreaders, mowers and many other systems.
However the underpinnings – flexible ladder-frame chassis, ‘drop-box’ portal hubs for unmatched ground clearance, three diff locks, coil springs and multi-ratio transmissions – are familiar to Unimog aficionados.
The principal differences between the familiar U4000/U5000 Unimogs and the U430 are, obviously, the cab and the overall ground clearance and chassis flexibility. The U430 doesn’t have the traditional ‘Mog torque-tube propshafts, nor does it have the same degree of wheel travel. However, for the travel aims of nearly all motorhome buyers, the U430’s configuration is more than adequate.
The stubby cab provides an outstanding forward and side view, due to the short front-end assembly and panoramic glass. However this forward positioning hasn’t compromised safety, Mercedes-Benz claims. The new Unimog complies with the highest safety standards, including ECE-R29/02, the internationally recognised standard for survival space of all the occupants in commercial vehicles; fire resistance inflammability test according to hazard regulation FMVSS 571.302 and roll-over-protection to OECD Standard Code 6.
Other safety initiatives include daytime running lights, ABS, seats with integrated three-point safety belts and headrests.
Adding to its flexibility is an option called VarioPilot. The steering box is mounted at the front of the left side chassis rail, but the steering wheel and instrument cluster can be unlocked from its natural LHD position and slid across the cab for right-hand-drive applications. This feature makes the U430 ideal for people who want a motorhome they can use to tour around the world.
Another option is CTI (Central Tyre Inflation),
operated from a dashboard switch.
The U430 is powered by ‘Benz’s Euro 6, OM 936 7.7-litre engine that puts out 220kW and 1200Nm.
Its fully synchronised electro-pneumatic transmission is different from that fitted to larger Unimogs. This new development combines a fuel-saving manual transmission with optional, infinitely variable hydrostatic traction drive and allows a swift change between the two types of drive.
The hydrostatic traction drive itself has two driving programs: the work mode for jobs needing a constant engine speed and the drive mode for infinitely variable acceleration with a variable engine speed.
The main box has eight forward and six reverse gears, engageable in three working and crawler gear groups. The choice between changing gears manually and automatically can be made simply by pressing a button.
A useful feature is Electronic Quick Reverse that makes it easier to change direction quickly when getting out of a wheel-rut bogging.
Despite its diversity the transmission is controlled by an EasyDrive control stalk, located behind the steering wheel, so the driver can control the direction of travel, gear and cruise control. There’s also a multifunction joystick, in addition to the normal accelerator pedal and brake.
We checked out the the U430 Earthcruiser during its construction in the company’s new Wollongong (NSW) factory and drove the finished motorhome.
The Earthcruiser Unimog U430 is built on the longest available wheelbase: a dimension that was developed primarily to suit the Earthcruiser motorhome module. Earthcruiser added a rear chassis extension to lengthen the available load space, before mounting a modified version of its successful motorhome
Options added to the basic spec’ included VarioPilot and tyre inflation and deflation on the fly, but the hydrostatic transmission wasn’t considered necessary for what is a recreational vehicle. The main box ratios are more than adequate for most owners’ needs.
The ‘Benz transmission can be driven as an automated manual, where shifts are done with computer control of clutch and selectors, or as a manual box, using a clutch pedal that drops down for the purpose. However, even in automated manual mode the box can be operated as a manual, without need for the clutch, by selecting ‘M’ rather than ‘A’ mode. That’s ideal for low-speed off-road situations such as deep sand and rock hopping, where gear shifting isn’t desirable.
For most driving conditions the transmission can be operated as an automated manual, letting the computer work out the correct gear. Shifts aren’t inherently smooth, partly because of the large ratio spread in the box, but with a little practice shift-shock can be modulated by accelerator pressure before and after each shift.
The U430’s cab is well insulated, preventing nearly all mechanical and road noise from intruding.
Ride quality in the Earthcruiser U430 was superb, with no suspension or tyre harshness. The big coils soaked up bumps and undulations without complaint, while handling was flat and predictable.
The tested weight was around nine tonnes and the U430 is rated at 12 tonnes GVM.
Given the weight of the U430 Earthcruiser it’s not surprising that Mark Fawcett, Earthcruiser’s principal, opted for four, vertically-operating hydraulic rams fore and aft, to lift the vehicle in the event of a tyre change, or a bogging. The huge rams operate independently, so they double as vehicle levellers when camping.
The proved Earthcruiser motorhome module sat neatly behind the U430 cab and access to its elevated position was eased by a concertina-stair arrangement that had broad treads and a gradual slope.
The interior layout in the evaluation machine had a transverse double bed and three optional pipe-cot bunks for kids. The shower/toilet module is cleverly positioned in the entry footwell, doubling as a ‘wet room’ at the top of the stairs.
A 220-litre fridge/freezer fitted under the kitchen bench and the dinette chairs doubled as transit seats, being fitted with seat belts to ADR requirements.
Equipments levels were high, as we’ve
come to expect from Earthcruiser, and included full air conditioning, backed up by a massive lithium battery bank and ample water and fuel storage.
An electric barbecue backed up the interior cooker and, naturally, there was a washing machine. A nice touch was integrated step ladders on both sides of the aft storage compartment.
The U430’s cab wall allowed a large walk-through opening from the front seats to the motorhome body and the various controls that used to grace the engine tunnel between the front seats had been moved elsewhere to allow easy people movement between cab and body.
Anything built on a Unimog chassis isn’t going to be cheap, so the haggling starts around 600 grand.