Mercedes-Benz and SsangYong vehicles come with automatic gearboxes with a manual mode called G-Tronic. In 1981, a 4-speed automatic gearbox called the first G-Tronic was introduced. The producer now makes a 9-speed G-Tronic transmission. These gears are all exclusive creations of Daimler AG and are distinguished by dependability, excellent performance, and the capacity to transmit large torques.
A traditional automatic transmission with a hydraulic torque converter and computerized management is the foundation of G-Tronic. It has a torque converter lockup as of the 1990s. Initially, this gave the driver the option to select the highest gear (one or more higher gears may have been shut out). In the future, it assisted in the implementation of a complete manual mode that was present on all subsequent iterations of this automatic transmission.
The 7G-Tronic
The 7G-Tronic gearbox is a fairly recent innovation in a race to advance. Mercedes was already firmly devoted to making the transmission simpler for the driver to operate during the 1930s. Mercedes achieved a new milestone in torque converter-based automatic transmissions in 2003 as it reached the previously unheard-of number of seven gears. The 7G Tronic’s key benefits include reduced average engine speed and fuel savings since there is more closed staggering and the best gear is always identified at the speed for a low rotational speed. By skipping intermediate gears, downshifting can be done more quickly, and overtaking can be done more quickly and smoothly. When moving quickly, the change in gears is hardly noticeable.
Mercedes’ first move toward automation was when “Overdrive” was installed in the model 770 “Grand Mercedes” that was driven by a suction system. It was not, however, until 1955 when equipped his 300 Adenauer with the first torque converter automatic gearbox, manufactured by Borg-Warner.
In 1957 the “Hydrak” was developed internally, a piloted clutch that combined a hydraulic clutch for starting and a dry mono-disc clutch for gear changes, although gear changes continued to be manual. They were an add-on that could be added to the 190, 219, and 220 S versions.
In 2005: 7G-Tronic: the first seven-speed torque converter automatic transmission. Taking advantage of the launch of the new ML, R and S classes, Mercedes repositioned the place of the gear lever, eliminating it from the usual place centered on the steering stem, mounting it on the console, and adding buttons to the steering wheel that enable sequential usage of the console in accordance with American preferences.
In 2008: The new SLs come equipped with a new feature in the evolution of the 7G-Tronic box, which performs the double-clutch maneuver for the first time in reductions, the model’s signature athletic sound while enhancing the march’s safety and smoothness throughout these maneuvers by eliminating the usual jerks with a well-timed stroke of the gas.
A year later, the SLS AMG makes its debut with the option to switch between four different transmission modes. This option is selectable from the “AMG Drive Unit,” which, when in the “Race Start” position with the self-locking differential added, provides a record-breaking rate of change and a significantly increased capacity for traction.
In 2010: The sixth generation of 7G-TRONIC PLUS automatic transmissions arrives. It provides among the most noticeable changes a reduced torque converter slip, hence lowering internal power losses, by taking advantage of the introduction of the new CL class (W216). For a vehicle of its category and displacement, the average engine speed in “ECO” mode is much lower with low accelerator load, indicating exceptionally tight specifications. Two years later, the SL line obtains the new Direct Select arrangement with a new gear lever design and “Shift by wire” technology, even if it still lacked the most recent iteration of the 7G-Tronic Plus.
This constant progression of technical advancements began with the Mercedes E 300 BlueTEC HYBRID and is still going strong today. When conditions permit, a 20 KW electric motor that is incorporated into the torque converter may be used in place of the 2,2 horsepower, 204-liter, four-cylinder diesel engine to help acceleration and recover energy during braking.
The 9G Tronic
In 2013: The 9g Tronic first came into the market. Debuting on the Mercedes E350 Blue TEC. After that, it was made fully available in the W222 S-Class model. It quickly became the norm for all Mercedes automobiles.
Although it offers more outstanding solutions to provide you a more effective and smoother driving experience, the 9G Tronic is based on the 7G Tronic architecture. The way the gearbox was designed was such that it always ensures the engine is in lower rev to give you an improved fuel efficiency of 10% compared to its predecessor, the 7G Tronic.
This variant is available with an MCT or a torque converter. There is no torque converter in the MCT unit, which is a standard 9G. The computer is built to accommodate the double-clutch capability, and the MCT is constructed with a wet clutch design.
7G Tronic and 9G Tronic compared
Compared to the previous 5-speed automatic gearbox, 7G-Tronic is more fuel-efficient, has faster intermediate sprints, and shorter acceleration times. Two reverse gear ratios are available. When downshifting, the gearbox may skip gears.
Additionally, it includes a torque converter lock-up on each of its seven gears, which allows for greater torque transmission and faster acceleration. To save weight, the transmission’s shell is built of magnesium alloy, a first for the sector. The Mercedes-Benz Stuttgart-Untertuerkheim factory in Germany, which is also the location of Daimler-Benz’s first manufacturing facility, is where the 7G-Tronic gearbox is made.
The 9G Tronic is the successor to this well-known 7G Tronic 7-speed gearbox and offers several advancements over its forerunner. It was a good several months before Range Rover when Mercedes unveiled the first-ever 9-speed automatic transmission made specifically for luxury cars. The 9G Tronic, will temporarily take the place of the 7G Tronic. It was fitted on four different variants of the CLS facelift after it was introduced and made its premiere on the E 350 Blue Tec model. Additionally, it is planned to be fitted in the ML, C, S, and next GLK variants of the E-Class.
The Mercedes E350 Blue Efficiency model debuted the 9G in 2013, and this model has the most glaring enhancements over the 9G Tronic. Although the E350 BE’s 0-60 mph timings are still remarkable at 6.6 seconds, it gets better gas mileage than its predecessor, getting 53.3 mpg as opposed to 51.4 mpg. With 138g of carbon dioxide emissions per 100 kilometers, this more recent gearbox is likewise kinder to the environment. This is an improvement above the 7G Tronic’s 144g per 100km performance.
Additionally, Mercedes-Benz boasts that the 9G Tronic, which makes its premiere, would consume just 5.3 liters of gasoline per 100 kilometers. With only 138g/km, the CO2 output is likewise considerably lower.
But the lengthy ratio between first and ninth gear is beneficial for efficiency as well as for improving driving comfort. In principle, a Mercedes engine performs admirably with just three or four gears due to the powerful 620Nm of torque produced by a 3-liter diesel engine at 1600 rpm. It becomes clear that it delivers even more driving comfort and refinement when you take into account the 9 gears.
Additional two gears: The additional two gears have a direct impact on the new gearbox’s efficiency. That’s because the ratio of the distance between the first and ninth gears is 9.15 different. It becomes essential in terms of efficiency because of this. As a result, the E 350 Blue Tec can travel farther at incredibly low rpm.
This implies that you may, for instance, cruise at a speed of 120 km/h with just 1350 rpm. Additionally, the Blue the E 350 Blue Tec can achieve its top speed of 250 km/h at just 2700 revs per minute.
Lightweight: Do not be deceived by the 9G Tronic’s extra two speeds and maximum 1000 Nm transferable torque. In actuality, this new transmission uses less room than the 7G Tronic it replaced. This transmission system weighs less than 100 kg and is also lighter. The gear’s case is made up of two halves.
The torque converter’s aluminum housing is the first of them. The transmission’s other housing is built of a magnesium alloy. The sump is also made of plastic by the manufacturer. Although the nine-speed gearbox has two more gears, it also has four semi-axles & six shift elements as compared to the seven that the 7G Tronic has.
Two pumps: The size of the pumps is another noteworthy improvement in the 9g Tronic. The primary axle is now situated near to the main pump, which is significantly smaller than the old one. Additionally, it is chain-driven and not directly powered; instead, an auxiliary-powered pump drives it.
With the primary goal of being acquainted with the start-stop system, this makes it simple to adjust the cooling and lubrication upon request. The improved hydraulic torque converter also boosts gearbox efficiency to 92%. This lessens the transmission loss between the transmission shaft, torque, and engine.
The gearbox features three settings, Sport, Manual, and Economy, exactly like the 7g Tronic Plus. M mode is a different temporary one that exists as well. This may only be used when using paddle shifters to change into specific ratios in the Economy and Sport modes. When manually shifting gears or when a sporty driving style is maintained, the mode stays in operation. The long-term Manual mode, which is offered together with the AMG Line package, is substantially different from this.
Torque converter. The hydrodynamic torque converter serves as the transmission’s driving component. The torque converter’s hydraulic circuit has been upgraded in the new 9G-TRONIC, resulting in a 92% gain in efficiency. This incredibly high number is crucial for fuel efficiency since it minimizes the losses caused by physics when the engine torque is transferred to the transmission’s input shaft. This component’s efficiency in the 2003 first-generation 7G-TRONIC was barely 85%.
Conclusion
An upgraded version of the 7G Tronic automatic transmission is the 9G Tronic. Almost every feature of the previous vehicle, including comfort and fuel economy, has been improved. Despite having two more gears, the latter model is lighter than the 7G Tronic variant.
The W7A 700 and W7A 400 (Wandler-7-Gang-Automatik bis 700 oder 400 Nm Eingangsdrehmoment; converter-7-gear-automatic with 516 or 295 ft-lb maximum input torque; type 722.9) are the foundational models for Mercedes-Benz’s seven-speed automatic gearbox, known as 7G-Tronic.
