On the road in the Mercedes-Benz Sprinter 7G-Tronic - Seven gears: comfortable, economical, eco-friendly

Oct 10, 2012
  • Lightning-fast, barely perceptible gearshifts
  • Skilfully synchronised drive train from a single source
  • Low-geared at the bottom, high-geared at the top – perfect for all types of application
  • Transmission uses pulling power of CDI engines
  • Manual intervention possible, but rarely needed
The Mercedes-Benz Sprinter and the new 7G-Tronic automatic transmission with torque converter – a comfortable, economical combination, which is particularly eco-friendly on the busy streets of the big city.
Lightning-fast, barely perceptible gearshifts
The transmission glides smoothly from first to second gear immediately after pulling away. After that it is difficult to follow the gearshifts: as quick as lightning and almost imperceptibly, the new 7G-Tronic automatic transmission in the Sprinter switches from one gear to the next. At a constant speed of 50 km/h, the test vehicle, a Sprinter 316 CDI panel van, is travelling though Düsseldorf at a cool 1200 rpm in sixth gear. Fuel consumption and CO2 emissions: low. Noise: extremely unobtrusive, both inside and out. Driver’s nerves: at ease.
Skilfully synchronised drive train from a single source
The new Sprinter skilfully combines a CDI engine and a seven-speed torque-converter transmission, both of which are perfectly attuned to one another – all the advantages of this van are highlighted by the drive train whose components originate from a single source. Gearshifting is extremely smooth, taking place at lightning speed. The tachometer needle and a slightly different noise frequency are the only indications to the driver that the gear has changed.
Compared with the tried-and-tested predecessor transmission with five gears, the developers at Mercedes-Benz have chosen the next-longest axle ratio in each case. Despite this, the Sprinter with 7G-Tronic automatic transmission demonstrates an eager response and vigorous propulsive power. The broad choice of seven gears is the basis for perfect synchronisation of the drive train.
Low-geared at the bottom, high-geared at the top – perfect for all types of application
Thanks to the low ratio of the first speed, the Sprinter with 7G-Tronic packs a punch when driving off, on uphill gradients and when laden. But at higher speeds, it coasts along at extremely moderate engine speeds, approximately 2100 rpm at 100 km/h in the case of the Sprinter 316 CDI. This lowers fuel consumption and thus CO2 emissions, as well as interior and exterior noise. Even someone who occasionally makes use of the top speed – rarely possible on the motorways in and around Düsseldorf – drives significantly under the rated engine speed of 3800 rpm.
But the automatic transmission shows its biggest advantages in the city. Here the driver can concentrate fully on the chaotic traffic of the big city – things can really heat up on the streets of Düsseldorf. This lessens the burden on the driver and increases safety.
Automatic transmission operates smoothly yet with spirit
The automatic transmission in the Sprinter operates with as much spirit as many of Düsseldorf's car drivers, yet smoothly at the same time. If the driver reduces the speed, the transmission calmly allows the engine speed to drop to approximately 1000 rpm before shifting down almost imperceptibly. When the driver requests full power via the accelerator pedal, it is quick to respond. When accelerating before pulling onto the motorway, for example. In this case the transmission and engine operate so effectively together that the automatic transmission kickdown seems almost unnecessary. At full throttle, the transmission allows the engine to operate up to the rated engine speed of 3800 rpm – the Sprinter has a large usable rpm range.
Transmission uses pulling power of CDI engines
That is a rare exception, however, since the transmission usually makes use of the high stability of the Sprinter's CDI engines when under load. This allows the engine to pull at low engine speed, preferring to work with power over performance. Hectic shifting and back-and-forth shifting are unknown in the 7G-Tronic Sprinter. On uphill gradients, too – found only on the outskirts of Düsseldorf – the transmission keeps cool.
Manual intervention possible, but rarely needed
Brief, manual intervention in the workings of the transmission is only recommended in extremely rare cases. A leftward tap against the selector lever causes the transmission to downshift. Helpful on downhill gradients to utilise the braking effect of the engine. A short movement of the lever to the right causes an upshift. But the transmission usually shifts to the next gear up in good time anyway. It is almost as if the technology can read the driver's mind.
Thus the Sprinter with a powerful diesel engine and 7G-Tronic automatic transmission reveals itself as an ideal combination for short-haul routes: comfortable while also economical and eco-friendly. One last test before returning the test vehicle: when and how fast will the 7G-Tronic Sprinter shift up during powerful acceleration from a standing start to 50 km/h? Completely in vain; the 7G-Tronic torque-converter transmission is much faster than the driver.
Mercedes-Benz E-Class: 7G-Tronic Plus transmission
Mercedes-Benz´s world-first seven-speed automatic transmission for passenger cars, the 7G-TRONIC, was premiered in 2003.