Our best truck yet

11 MinutesBy NZ Trucking magazineMay 2, 2017

New Zealand Trucking was invited to Australia recently to check out the new Kenworth T610 range and test drive the model on the Mt Cotton track in Queensland. Kenworth say the new model has gone through unparalleled testing and validation, and we were keen to try it out.

Although the cab is a joint venture between three PACCAR truck manufacturers – Kenworth US, Peterbilt, and Kenworth Australia, the new Australian cab has had a further $A20m invested in research and development to meet the Australasian market. Kenworth Australia point out the T610 has been their largest single truck development investment to date.

The new look

Kenworth had several configurations at Mt Cotton, with four different cabs, the T610 and the T610SAR, both of which are available in day cab or 860mm sleeper cab options.

The cabs are significantly wider, which is especially noticeable in the way the doors cover the fuel tanks and the exhaust stacks hug the side of the cab. The big front single-piece screen is higher than the doors and the aerodynamic mirrors. They‘re distinctly different doors in the way they blend into the cab lines and the way the windows are cut low at the front.

The SAR keeps a traditional upright grille, but the cowling between the bonnet and door comfortably supports the air cleaners, without them impacting on the door opening.

Photo: Left to right: Visbility from the driver’s seat is excellent. Cumins 12-litre engine is renamed the X15

The new cab

The primary difference is the cab – which is almost 300mm wider (between the B pillars) and much more refined than its predecessor.
PACCAR in the US recently said they spent $US400m designing and building the T680 cab. It‘s the T680 cab that is the basis of the new Australian cab.

Kenworth director of sales and marketing Brad May says from a quality viewpoint the totally new cab is a step up, but it retains the  Kenworth look and feel. It‘s this ‘feel‘ that Kenworth Australia has done an amazing job of creating, because it feels like a modernised and improved Kenworth cab, not a completely different cab. The Australians decided to ‘Australianise‘ their new model, and their engineers have done a great job maintaining the right image. When asked if it is an American truck, May responds, “Nothing could be further from the truth”.

The cab metalwork is almost all aluminium, with the exception of a few steel supports. May points out that dimensional accuracy is an important feature of the new design, especially around the door fitment and dash assembly. He adds that it‘s been ‘over-tested‘, especially when it comes to vibrations simulating road corrugations. Interestingly, the overall cab weight is less than the cab it‘s replacing.

Although the cabs are built in the US and imported assembled, the structure of the Australian cab, particularly the floor and firewall, is significantly different from the American models.

The engine and gearbox

The T610 is powered by a Cummins X15 engine, in a range of outputs from 485hp to 600hp and 1650lb/ft to 2050lb/ft.

Mike Fowler, Cummins director of on-highway business, says the engine software has been especially designed to achieve maximum performance in the T610 application. However, he points out that it is basically the ISXe5 15-litre engine that was originally introduced in 2013 to replace the EGR version.

Cummins have dropped the ISX naming convention and are renaming their engines with an X preface. Eaton manual or Ultrashift Plus transmissions are available.

Fowler points out that Cummins and Eaton worked closely on the match-up, particularly the electronic interface between the engine and the Ultrashift Plus AMT. He says that previously the relationship between the engine and transmission was not harmonious, but they now have optimised shift points and further efficiencies are gained through ADEPT (Advance Dynamic Efficient Powertrain) technology.

ADEPT is a group of electronic interactions that take place between the X15 engine and Ultrashift Plus. Cummins say, “The system continuously makes minor adjustments to speed, power and transmission gear to take advantage of vehicle momentum, maximising efficiency and using less fuel while allowing the driver to concentrate on the road ahead”.

Photo: The traditional upholstery Kenworth buyers expect is still there.

In the driver‘s seat

Getting into the truck is easy, mainly because the door opening is so wide. It may well be the door shape that is the most important change for the driver; it‘s wider, the window is lower, it opens further and seals better. The clunk you get when closing the door is positively different from that of the old door.

Once in the cab the extra width feels a lot more than a mere 300mm; the gap between the seats is vastly different, and especially useful in the sleeper cabs. But the traditional upholstery is there. It‘s likely that Kenworth Australia had to fight to ensure they didn‘t get a plastic vocational style interior from the US. This interior continues to resonate with the Kenworth enthusiast.

The vision is significantly better too. The big screen is fine, but it‘s the view out the side windows that is much better; the A pillar and mirror have much less effect on vision than in the previous cab. The lower window cut in the doors means the mirrors can be mounted low and the result is that the mirrors can mostly be looked over the top of, and there‘s a decent gap between the A pillar and mirror.

The hard trim is a pleasant and practical grey colour, called grey ember. The Aussies specified this as opposed to the light tan used in the US, and the soft trim is available in a range of three colours, with two more to be added soon.

The dash is generally functional rather than flash; although all the full gauge package is still available and the layout is familiar, the grey plastic trim, silver bezels and bit of wood trim indicate that the T610 is a working truck. The dash is modern and stylish; Kenworth‘s Smart Wheel is a great addition and everything‘s within comfortable reach.

There are plenty of screws visible on the dash; in a reversal of the modern practice of using plastic clips and hidden fixings, Kenworth‘s engineers decided robustness and serviceability were more important than looks. It‘s a move that we applaud; great idea guys. They also reckon the dash is mounted extremely strongly and will never shake loose; it‘s one of the factors they tested to more than double the normal test standards.

Photo: The T610 is a smart looking cab, even in day cab form.

On the road

The test trucks came in various configurations and gross weights of up to 76 tonne. This allowed plenty of opportunities for experimentation and the long straight was open, allowing a top speed of about 90kph to be reached. On-road performance is typical Kenworth excellence; the performance and handling of the truck is enhanced by the better cab, improved driver environment and excellent vision.

The dogleg in the steering shaft between the steering wheel and the steering box is no longer there. Thanks to the wider cab a straight linkage can be used; there was some suggestion that this improved the feel of the steering, but we didn‘t notice it.

The communication between the engine and transmission was noticeably better. We have been a little disappointed with the Eaton Ultrashift versions behind the 15-litre Cummins engines in the past, but there is a definite impro vement in the T610 – the optimised shift points Mike Fowler talked about are not just marketing talk – the T610 walks the talk.

Is it Kenworth‘s best truck yet?

It will take years, if not decades, for a model to reach the giddy status of Kenworth‘s best truck, and no one will agree on what measurements should be used to determine the result anyway. But putting our emotions and traditional favourites aside, we saw no reason why the T610 shouldn‘t be a contender.

If the cost figures that are rumoured are anywhere near correct, the model will be well positioned in the value for money category.