TRANSMISSIONS
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CM couldn’t have picked three more diverse transmissions if it had tried, and it was the manual overdrive six-speed in Renault’s Midlum that felt the most alien and required the most thought.
Neutral sits between second and fourth and has the narrowest gear range, which requires the driver to use first gear every time for a standing start and to use each gear through the range to top.
Block-changes can be made coming down the box to use the exhaust brake, which delivers up to 130kW with the revs above 2,000rpm. On the motorway and on the level the six-speed is perfect, but on the hill climbs those slightly wider gaps between second, third and fourth, compared with its competitors, force the driver to be more proactive (see engines).
The eight-speed range-change in the Scania, although an option, felt the most comfortable. As a four-over-four it has been industry standard for longer than many drivers can remember. Start in second on the level, block-change to fourth, and then into the high-range for single changes to the top. With an exhaust brake on the brake pedal, the driver can change down in block to raise revs to get the best from it.
However, it was MAN’s 12-speed Tipmatic overdrive gearbox that took the day. Select D (for drive) and away you go. The driver might want to select manual on the motorway to stop the gearbox changing down when it reaches a shallow hill climb, or prevent any unwanted changes when reaching the brow of a hill, otherwise the transmission gets on with the job in hand.
Its eagerness to change down once the engine starts to work on a hill, is the only downside.
Automation requires the driver to be gentler on the accelerator; put your foot down and it will drive up the revs before a change, eradicating any benefits it might bring. Another benefit of automation is that it reduces wear and tear on subsidiary items such as the clutch, compared with a manual transmission.