DRIVEN
There
was a time when your choice of truck had no bearing on the choice of power plant. You could basically have any model of truck you liked, then specify the engine, gearbox and diff ratios to your liking. The modern era is quite a different story, with specific models targeted at individual market segments, and in some cases specific jobs. Engine choices are also limited, depending on the manufacturer and their corporate alliances. This has proven quite a problem for Kenworth in recent years, since the sale of Detroit Diesel to Daimler and with Caterpillar’s withdrawal from the on-highway market. For Kenworth buyers this meant only one choice of engine manufacturer, regardless of horsepower rating, that being Cummins. In another twist of fate for Kenworth, the last generation of Cummins EGR engines suffered from reliability issues, leading some long-term customers to look elsewhere for their new equipment. The lack of a reliable 13-litre engine option was a serious concern
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for both customers and dealers, but that scenario has now changed, thanks to the recent release of the PACCAR MX13 in Kenworth T4 models. Neither the Kenworth T4 series nor the PACCAR MX13 engine is new to the Australian market. The T409 and T409SAR are well regarded for their strength, durability and versatility. Suitable for many tasks, from truck and dog to 26-metre B-double duties, this platform is well proven and well accepted by both the drivers, and the operators who buy them. The PACCAR MX13 has been on our shores for years, under the cab of the DAF XF and CF models, and over that time has proven to be both reliable and efficient. The combination of the two offers operators a solution, and the confidence that only comes from proven components. The PACCAR MX13 is a 12.9-litre, in-line six that uses a single stage turbocharger and high-pressure (2,000 bar) fuel injection to achieve a maximum power output of 510 hp (375 kW) and 1850 lb-ft (2500 Nm) of torque (equal to the optional 15-litre ISXe5). A lower rating of 460 hp (340 kW) and 1700 lb-ft (2300 Nm) of torque is also available for those who prefer to save on their horsepower, offering possible fuel savings on single trailer or light-duty tasks.
BRAND NAMES Both the block and the head are built using Compact Graphite Iron (CGI), a stronger but lighter material than cast iron, providing significant weight savings over the Cummins options. The combustion process is optimised to reduce particulate emissions, and combined with Selective Catalytic Reduction (SCR, or AdBlue) brings the MX13 into line with Euro 5 emission regulations. While it would seem a simple process to install a 13-litre Euro engine under the bonnet of an American truck, the engineering was actually a difficult task. Not so much the fitment of the engine, but the integration of the 24-volt electrics required to operate all of the ancillary equipment. To make this simpler, Kenworth engineers have converted the whole electrical system throughout the truck to 24 volts, with voltage reducers enabling fitment of standard radios and operation of other 12-volt equipment. The change will be barely noticeable to operators and drivers, and the increase in availability of multi-volt electrical equipment, including lights and in-cab gadgets, should mean there will be very few electrical-related issues. The actual positioning of the engine is low in the chassis, keeping the centre of gravity low and providing for good handling characteristics. There is certainly plenty of room around the engine for access, though some components that are positioned low on the side of the block may be difficult to get to. The oil filler cap is way back under the cab, but a replacement filler line is positioned for easy access to top up the sump. The good news for the traditionalists is that you can still have external air intakes and twin stacks up the side of the cab, while, for those looking for aero advantage, a low-mounted exhaust can be directed out under the chassis.
The PACCAR MX13 engine is right at home in the latest T409 and T409SAR models from Kenworth.
To demonstrate the ability of the MX in the T409, Kenworth arranged for PowerTorque to drive a few different variants, with different trailer combinations and weights, and a mixture of manual and AMT Eaton transmissions. Also on hand were a couple of DAF models – one B-double XF105 with the 510 hp MX loaded to 46-tonnes, and one CF with the 460 hp MX towing a single trailer loaded to 35-tonnes. Interestingly, the latter was fitted with a synchromesh manual transmission, while the XF used the 16-speed ZF AMT. Upon start up, the sound was obviously very different from the usual Cummins. At idle the MX13 was smooth and quiet, and under acceleration it was obvious from the noise levels inside the cab that something had changed. While there was still enough noise to keep the Kenworth purist happy, it was not as harsh, or rough, as the American iron. The engine sound was still satisfying, but very different.
BRAND NAMES Kenworth Australia moves towards vertical integration as it brings the PACCAR engine range into the order books. Dave Whyte reports PowerTorque ISSUE 59
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DRIVEN
The MX13 will be somewhat of a quandary to some Kenworth customers – do they stick with the American Cummins or go with the lighter, potentially more efficient European powerplant? With the window down, noise levels were still low, even while negotiating steep climbs under load. At one stage, in the T409SAR towing a B-double loaded to 62-tonnes, I had to stop part way through a steep climb due a slow vehicle ahead. With the trailers still tracking around the corner, and a fairly steep grade underneath, the MX13 pulled away without the need for crawler gear, and continued to accelerate up the grade, albeit using half gear steps. Progress was good, however, and even the Kenworth representative on board was surprised at the pulling power of the PACCAR engine. Around the short test track we had available, I took the opportunity to drive all but one of the units available – meaning I had covered B-double combinations up to 62-tonnes with both manual and AMT Eaton transmissions, single trailer combinations at 35-tonnes with both manual and AMT transmissions and one B-double at 45-tonnes behind the DAF XF105 with a 16-speed ZF AMT. Throughout the day I was frequently surprised by the performance of the 13-litre MX. In a market where 15-litre engines are the norm, this step back from a big-bore engine proved more than capable. With equally impressive engine braking from the combination exhaust and engine brake setup, there was no reason to doubt the MX13’s ability or suitability for the B-double market. It seems strange to me that a much smaller engine, 13-litre as opposed to 15-litre, can produce the same torque, over a wider rev range, and with less noise. Reduced weight and promises of good fuel efficiency would seem to be too good to be true, but can a 13-litre engine maintain its integrity over years of working with heavy loads in Aussie conditions?
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Having just returned from America, I can tell you that the MX13 engine is found under the bonnets of almost half of the new trucks that roll out of PACCAR plants over there that wear the Kenworth and Peterbilt badges on their bonnets. It would seem at first sight that PACCAR has managed to sell ice to the Eskimos, so to speak, with the supply of an engine with very European origins in place of traditional American iron. In reality, although the PACCAR MX13-litre has proven its credentials in the European markets, the US version is produced in the PACCAR engine plant in Columbus, Mississippi, in a range of capacities from 380-500 hp at Euro 6 emissions levels with outputs of 1,450-1,850 lb-ft of torque. PowerTorque was the first trucking magazine to be invited to tour the plant just after it opened back in 2010. This $400 million brand-new engine plant adds a deep South Cajun origin rather than Dutch clogs to the supply chain, and in so doing it cements the future of the PACCAR brand in engine supply. Last year PACCAR reported record annual revenues of $17.12 billion and net income of $1.17 billion. “PACCAR achieved the third best annual net profit in the company’s history and the 75th consecutive year of net income,” said Mark Pigott, chairman and chief executive officer. With that level of success amidst a world of nervous analysts, it makes the argument in favour of the MX13 and its derivatives extremely strong.