by John Kendall • 1990 brought us the Renault Magnum,
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1993 saw the arrival of the Volvo FH. Now it's Mercedes' turn to set the pace. The Actros is not only good to drive, but the on-board "Telligent" electronic systems set a new benchmark for heavy trucks.
CM drove three Actros vee-six models in Germany, a 389hp 1840 LS at 40 tonnes GCW, 422hp 1843 with Telligent automated gearshift at the same weight and a 308hp 1831 at 36 tonnes GCW.
The 1840 was equipped with the "L" long distance sleeper cab, Telligent "manual" gearshift and a Voith retarder. Three broad steps and wide opening doors gave easy entry. With its standard high roof and headroom over the footwells of 1.92m, the cab has a spacious feel (Mercedes claims there is 47% more space inside than in its predecessor).
Under-bunk stowage is split into three bins accessed from separate locking covers—the bunk cushion is split into three. Both outer lockers can be accessed from outside. Above the screen there is a locker on the driver's side and a full-width tray underneath it. There are door lockers both sides and a storage box between the seats is optional. This 1840 was fitted with an electrically adjustable, air-suspended, heated driving seat.
The warning panel will display any faults logged by the Telligent diagnostic system. It also shows the elapsed time since the last service. Mercedes claims that daily checks of oil and coolant are not necessary, as low fluid levels will also be shown on the display.
This 1840 was fitted with the standard "Telligent" gearshift system. Drivers used to Mercedes EPS will need a few minutes to take in the details of the Telligent shift.
The gear "lever" only moves forward and back and is fitted with a push button each side. In front of the lever is a paddle type switch which selects gear splits.
Upward changes are made by pushing the lever forward, downward by pulling it back. Similarly upward splits are made by pulling the paddle up and down splits by pushing it down.
Pulling away is simple: dip the clutch, push the lever forward and the dash mounted gear display shows the pre-programmed starting gear. In the 1840 this was 211, but this could be changed using the lever or splitter switch, say for a hill start. After that we drove off as normal.
The next gear can be preselected up to 10 seconds before
it is needed. Each time the sy:,tern decides which gear is appro. priate and displays it on the dashboard indicator panel. T, select it, dip the clutch, wait fl an audible click and feed in the clutch.
If you decide the gear offered is not the best choice, the lever and splitter can be used to choose another gear. A buzzer sounds if the gear step is too large and the system's selection will be used instead.
Splitter switch
There is yet another optical. If the driver wants to change up m single gear steps, simply cress the button at the end of the ever nearest the driver and move the lever forward. Using the sp itter switch as well can give a one and a half gear step.
Slowing down or stopping at a junction is straightfonvarcl. All the driver needs to do is pu the lever back when a lower gr is needed and the gearbox will offer what it thinks is the best ratio. To select neutral, press the button at the opposite end c the lever from the driver. A cut-out
prevents accidental selection on the move.
In practice the system is simple to use and offers a quicker change than its EPS predecessor. If the driver accepts the selection offered by the gearbox, there is no need to think about which gear to select, which in busy traffic allows full concentration on the road.
Our test vehicle had only covered around 6,0001cm and the 12litre vee-six felt tight compared with the higher mileage 1843 and 1831 we drove later.
We found that engine revs took longer to fall off in gear changes than the other two trucks and engine noise was more noticeable and became intrusive at times.
By comparison, road and wind noise were well muted.
Standard for the "L" cab on the 1840 is four-point coil springs and dampers with a front anti-roll bar. This is accompanied by parabolic springs on the front axle and four-bag air suspension at the rear. Cab roll was kept in check and the ride quality was generally very good.
This 1840 was fitted with a Voith retarder and the control for the engine brake, constant throttle brake and retarder are integrated on the right-hand column stalk. The maximum speed can be set automatically and on this setting the retarder/engine brakes can also be triggered by light pressure on the brake pedal. Mercedes says its constant throttle engine brake is more powerful on the 500 series engines. In practice we found it was as effective as the retarder on motorway descents, if the engine is spinning at around 2,000rpm. As many hauliers find the cost of a retarder prohibitive, it is reassuring to know that the constant throttle brake is a standard fitting.
We drove the 1843 around a mixed motorway/A-road route—a good choice for testing the automated gearshift system.
Pulling away needed a different procedure. This involved pressing the button on the end o selector next to the drive pushing the lever forward. that, gear changes were : automatically and very srr ly. Downward changes accompanied by a blip o throttle.
Changes could also be• manually by using the selector. As with the ME system, the computer picke gear it felt was best for th cumstances. Full manual ride could be chosen by sN ing from automatic to nu mode with a rocker switch to the selector lever. This 1; give manual only changes the lever and splitter switct
Engine noise was node' quieter than the 1840, bu mileage recorder was sho around 34,000km and engine felt more responsive The 1831 could prove to popular choice for distrib fleets. Our test vehicle ( with the "S" day cab. Thi four-point suspension but rubber cushions on the cat ots at the front with s absorbers and spring strc the back. Chassis susper was steel at the front and the rear axle. Even so, the quality was not notably v than the sleeper-cabbed mo
Lowest powered
The lowest powered varia the vee-six felt much liv than we expected from 3 pulling 36 tonnes. No dout 14% improvement in to over the SK 1831 helped. day cab appeared to offer sonable stowage and a pie; working environment.
We will have to test specification Actros befor reach any conclusions, but impressions are that the A could be the new standar which heavy trucks are jut The Telligent control and r toting systems make Actro most advanced truck avai today and the benefits fot vers and operators shoul available from day one.
If it doesn't turn out to b best European heavy truclare at least sure that the A is the most significant launched in the '90s.
E Mercedes is likely to fc Volvo and list Actro.s moth actual selling prices. These be announced before the launch in October. First deliveries will be before the of the year.