Drivetrain Punching Above its Weight

drivetrain punching above its weight.

Fitted in the latest Hino 500 Series standard cab models, the A05C engine is part of a drivetrain punching above its weight. With a swept volume of 5,123 cubic centimetres, around the same cubic capacity as the average Ford and Holden V8 car engines of the ‘80s and ‘90s, it has been deliberately over-engineered to enable an extended service life under arduous operating conditions. 

Such is the robust nature and design of this engine, with mostly highway running a service life of one-million kilometres should be attainable, provided the appropriate servicing procedures and intervals are maintained. 

Key to the strength of this engine is that it is a four-cylinder derivative of the six-cylinder A09 engine which powers the heavy-duty 700 Series trucks in Japan and the heavy-duty versions of the 500 Series Wide Cab models in Australia. 

As such, the A05C engine has the same robust construction as its big brother including 90mm diameter crankshaft main bearing journals and a high-rigidity engine block, both of which bode well for a long, trouble-free service life. 

In performance terms, the A05C comes with three different ratings depending on the model. The FC 1124 and FD 1124 models share ratings of 240hp at 2,300rpm and 794Nm of torque at 1,400rpm, while the FE 1424 crew models harness 240hp at 2,300rpm and 833Nm at 1,400rpm. Meanwhile, the range-topping FD 1126 and FE 1426 models boast 260hp at 2,300rpm and a healthy 882Nm at 1400rpm.

 

drivetrain punching above its weight.

A-Class Allison in the Drivetrain Punching Above its Weight

The engine is but one part of the powertrain package, with the quality and compatibility of the transmission behind it playing an equally important role in determining the overall performance of the vehicle. 

Whether negotiating peak hour traffic snarls, cruising at 100km/h on the highway or powering up the steepest climb of the Great Dividing Range, the Allison auto never fails to optimise every last ounce of power and torque from the engine, contributing to excellent fuel economy and superb drivability.  

There are, in fact, a number of reasons why the modern-day Allison automatic has effectively relegated the manual transmission in medium-duty trucks to the dinosaur era. For a start, there’s the obvious ease of driving aspect which plays a big part in reducing driver fatigue during long periods behind the wheel. 

In addition, the intrinsic design of the auto provides a couple of clear advantages over manual and automated manual transmissions (AMT), particularly when accelerating from rest and when climbing hills. Firstly, whenever the lock-up clutch is disengaged the stator inside the torque convertor provides a torque multiplication effect by redirecting oil flow from the turbine back to the impeller, thus increasing the torque or turning force produced by the impeller above and beyond the maximum torque level produced by the engine itself. 

Further to this, the shifts are lightning quick meaning virtually no break in power delivery between gears. On top of all that, as previously mentioned, the unit features a lock-up clutch in the torque converter which activates between second and sixth gears, effectively providing direct drive and eliminating inherent torque converter slippage which robs power and fuel efficiency. 

All of these features working in harmony proved a boon during my trip which traversed some of the most mountainous terrain on the eastern seaboard between Brisbane and Sydney. 

While obviously due to its three-tonne payload the Hino was a tad steady on the steeper climbs, it nonetheless displayed a gritty determination that enabled a relatively respectable velocity to be maintained and the ‘smarts’ to keep the engine operating in the most economical and torque-rich band between 1,200 and 1,600rpm. 

 

drivetrain punching above its weight.