New Car Test - Holden One Tonner

After years of seeing tradesmen flocking to Ford to buy Falcon cab chassis vehicles, Holden has bitten the bullet and reintroduced the One Tonner. (The last One Tonner was the WB model, phased out way back in 1985.) But while the new One Tonner is unashamedly a commercial vehicle, with its leaf-sprung solid rear axle and large payload, it's also one available in S configuration with the high-stepping 5.7-litre V8 and manual 6-speed 'box.

Perhaps it can be a good recreational toy as well? We decided to find out.

Equipped with the optional hardwood and steel tray (it's $1903, taking the total price to $38,373), the One Tonner S gets an interior equipment level close to the SV8 Commodore model - but misses out an a passenger side airbag (it's available as an optional extra). The cabin is all-Commodore - the instrument cluster, trip computer, seats, steering wheel, door trims, dashboard, HVAC controls and so on are straight out of other models.

But something that we haven't experienced before in a Commodore V8 is the gearbox noise - presumably because of reduced soundproofing, the noise of cog-swapper was obvious. In fact, noise levels are up a bit all-round - at highway speeds there's the deep thrumming noise generated by the aerodynamic wake departing only centimetres behind the occupants' heads, and the suspension in the test car could be heard creaking and groaning occasionally. However, for a commercial vehicle, NVH (noise, vibration, harshness) is very well suppressed.

Despite the change in rear suspension from the semi-trailing arms (with a toe-control link) design used on the rest of the Commodore range to a very basic leaf-sprung solid rear axle, and despite the fitment of Bridgestone Dueller A/T 215/65 light truck tyres, the engine in the S remains the familiar 225kW Gen III 5.7 V8. When you look the chassis tune, that's an awful lot of power ...

However, the Holden engineers have done a very good job of taming the handling. Sure, the One Tonner will power-oversteer quite easily (there's no traction control) and in wet conditions the tail can easily go walkabout under power. But the standard LSD, progressive tune of the rear leafs, and long wheelbase of the vehicle means that things happen relatively slowly: perhaps surprisingly, this isn't a vehicle to snap-out on you.

The ride is also far better than we expected. When unladen, the stiffness of the rear can be felt, but it's much less than that of the Rodeo that we recently tested (which has a far lower load carrying capacity, too!). Even on a bumpy country road, the rear doesn't hop around much at all.

All that said, this is the worse-handling full-size Holden that we have driven in recent memory - the tyres also having little grip and adding a large dose of vagueness to the steering. It's all dynamically light-years away from the excellent Holden SS ute - before we go any further, the question above can be answered. This is much more a tradesman's vehicle than one that'll be happy with a few trailbikes on the back and towing a ski boat a few hundred kilometres.

So as a commercial vehicle, how does it stack up? Pretty well - but it could be so much better.

The biggest downer is that the driveline retains the same stupid moonshot gearing of the V8 sedans. We're talking gearing so high that down-changes from 6^th need to be made for the (unladen!) One Tonner to climb relatively slight freeway hills, gearing so tall that even up to 80 km/h it's best to not be higher in the 'box than 4^th. The engine really only becomes responsive above 2000 rpm, and that means 6^th is a largely useless gear and even 5^th is rarely used.

Add a load on the back and a heavy trailer and the tallness of the gearing - even first - would be a major hindrance.

The conversion from sedan to One Tonner has also highlighted two other aspects that could have been done better. At waist height the optional tray's about 150mm wider each side than the cabin - but the outside rear vision mirrors remain standard Commodore. The result is that most of the rear view is filled with a nice image of the tray.... The inside mirror, too, should have been altered in design for the new vehicle. With the rear window much closer to the windscreen than in the sedan, the mirror could have been lengthened to take advantage of the wider rear view that's now possible.

The ventilation also doesn't seem to have made the transition from ute or sedan to One Tonner with its integrity kept intact. Flow-through ventilation in the vehicle is poor, needing the fan speed set to '2' even in 20 degree C ambient conditions.

Storage space inside the cabin is adequate. In addition to the normal Commodore centre console compartment and door pockets, there are two storage compartments located in the rear bulkhead. Items can also be put on the floor behind the seats - but since there's already a jack and jack-handle there, the utility of the space is reduced. Talking of the spare wheel, it's a non-standard steel rim fitted with a normal tyre - not the specially developed light truck tyres found on the other four wheels. The spare wheel is mounted under the rear of the vehicle.

The whole reason for existence of the One Tonner is carrying things - and at that it's excellent. The tray is enormous; you don't realise just how big until you start stacking goods in there. All three sides drop down, but it has a very high loading lip (odd, when there's plenty of clear space to be seen beneath the hardwood floor). However the tray metalwork isn't powdercoated - it's just normal paint - and the test vehicle had all the bolt heads handpainted in matt black paint, rather than the sprayed gloss of the rest of the tray sides. A good safety feature is the extensive protective grille over the rear window, while another trick feature is the step built into either side of the front of the tray.

The performance is much as you'll find in any other V8 Commodore - which is to say, very good. We recorded an unladen 0-100 km/h in the mid sevens, but - and as we've found with all cars equipped with these motors - very poor fuel consumption. Despite a large proportion of the test being with the vehicle unladen and driven on freeways, we struggled to achieve better than 15 litres/100km.

In short, if you're after a practical recreational toy with two doors and a tray, go for the Ute. But if you need a tray-top with greater carrying capacity but all the comforts of home, the One Tonner meets the needs admirably.

Why you would: Huge carrying capacity Ride and handling (for this type of commercial vehicle) good Comfortable and well-equipped Strong performance Why you wouldn't: Gearing far too high Poor fuel consumption Mirrors not well optimised for new role

The One Tonner was provided for this test by Holden

According to Holden: How to Turn a Ute into a One-Tonner Engineering work on the new Holden One Tonner commenced in 2000. The total program cost $55 million with more than 275,000 staff hours, 250 computer simulations and 350,000 durability and test kilometres expended in its development. One Tonner Cab Chassis utilises a part monocoque, part chassis frame construction that incorporates a unique 'torque arm' system. Most conventional pick ups utilise a separate chassis frame with front cab and rear box on top. With this 'torque box' system it is difficult to achieve a joint of optimum stiffness and durability in the frame to cab transition. Holden has taken a different approach: first by cutting behind the rear glass of the Ute cab structure. Additional reinforcement beams allow a separate frame structure to be bolted, rather than welded in place. Bolted joints have the advantage over surface welding of securing a complete cross section. The box section is stabilised with internal webbing for a rigid connection. The 'torque arm' consists of two vertical uprights at the front of the chassis frame bolted to the back of the reinforced cab at the bottom and top. Each arm creates a stronger joint because the load from frame to cab structure is shared across several points. A bolted frame such as this also allows the use of heavier gauge materials because it negates the problem of welding thick gauge to thin gauge. Specific materials and gauges can be chosen for the frame, independent of the cab structure. Finite Element Analysis (FEA) was employed to meet targets for stiffness, proof load cases and full vehicle crash simulation. Optimal structural integrity against maximum loading was attained through sectional and joint analysis. Hundreds of computer modelling scenarios were proven through additional noise and vibration validation, durability, and crash testing on actual prototypes. Analyses included: full body torsional stiffness of 12,950 Newton metres per degree; full body bending stiffness to achieve increased resistance to bend as much as 14 per cent in the longitudinal direction and 50 per cent transversely over a monocoque construction Ute; tow-bar design and development to allow towing up to 2100 kg; and full body modal analysis. Chassis The One Tonner uses a rear multi-spring suspension and live rear axle, rated to 1800 kilograms. Semi-elliptic, variable rate, four-leaf spring geometry is used, with the top leaf varying in thickness from 10 to 8mm. Front suspension is tuned to the rear, and the stabiliser bar, dampers and spring rates have been altered. The front stabiliser bar is 28mm, compared to 27mm in the sedan. Dampers are re-rated. Steering calibrations which change the split of power assistance versus driver assistance when turning the steering wheel away from the "on centre" position, in addition to increased torsion bar stiffness and power steering valve revision, are specific to the vehicle. Wheels and tyres are heavy duty to cope with increased loads. The One Tonner S has five-spoke 16 inch alloys, the One Tonner has 15 inch steel rims. Both wheels are rated to 900 kilograms - an increase of 30 per cent over the Ute wheel specification. Unique 215/65 light commercial tyres have also been developed to deal with these loads. One Tonner shares the Holden Ute's ventilated front disc and four channel ABS (One Tonner S). Calibrations made to Ute's load sensing brake proportioning valve give the One Tonner optimum front-to-rear braking balance under heavy duty load conditions. One Tonner has axle loads of 1180 and 1800kg at the front and rear respectively. Gross Vehicle Mass is 2826kg. Payloads, after allowances for fuel, passengers and accessories, range up to more than 1000kg in typical work situations.