Maruti Suzuki Celerio YL7 (A-Star/Estilo replacement) to sport semi-automatic gearbox

Snapshot: The next-generation Suzuki Alto will be called the Maruti Suzuki Celerio in the Indian car market. In a first for the Indian car industry, Maruti Suzuki is likely to offer a semi-automatic gearbox on the Celerio hatchback.

We’re weeks away from the 2014 Indian Auto Expo, a biennial motor show that is India’s biggest. The country’s leading car maker Maruti Suzuki will unveil the production version of the YL7 codenamed hatchback at the Auto Expo. Dubbed the Celerio for the Indian market, the B-Segment hatchback is a global product that will sell worldwide as the Suzuki Alto.

In India, the Celerio has been touted as a replacement to two slow selling hatchbacks in Maruti Suzuki’s car line up, the A-Star and the Estilo. First showcased to the world as the A-Wind concept at last year’s Bangkok Motor Show, the Celerio will get mild styling changes from the concept version such as production alloy wheels, non-LED head lamps and tail lamps, and toned-down interiors.

According to a report on TheEconomicTimes, the Celerio will be the first Indian hatchback to sport a semi-automatic gearbox. A semi-automatic gearbox, also known as the Manumatic, is a manual gearbox without the manual clutch. Semi-automatic gearboxes are less expensive than full blown automatics (torque converters) while also being lighter and more fuel efficient. Of course, the biggest advantage of a semi-automatic is the elimination of the manual clutch.

How does a semi-automatic gearbox work?

Here’s a broad explanation.

What does the clutch do?

It acts as an interface between the engine and gearbox (transmission) and allows for smooth transfer of torque of the engine to the wheels of the car through the gearbox. The clutch can be operated either manually, through a foot operated pedal in the driver’s footwell or automatically, as in the cases of automatic and semi-automatic gearboxes.

Click here to read CarToq’s exclusive feature story on when you need to replace your car’s clutch plates. 

Coming to the semi-automatic gearbox’s working, it eliminates the clutch pedal in the driver’s footwell, and instead makes do with a hydraulic clutch that works on inputs from the car’s electronic control unit (ECU). When a driver shifts up (say 1st gear to 2nd and so on), the sensors sense speed of the vehicle and engine rpm and automatically engage/deploy the hydraulic clutch for the gear shifting process. A similar process takes place when the driver shifts gears down (5th to 4th and so on). The timing of the clutch’s engagement in a semi-automatic is very precise as it is governed by sensors that are more efficient than most human beings, F1 drivers and fighter pilots not included.

Shifting gears on a semi-automatic gearbox,

In a semi-automatic gearbox, the traditional H-layout of a manual gearbox is missing.  Instead the driver can only shift forward and backward. The gearbox has three modes, D, R and N. D stands for drive and in drive-mode, moving/pushing the gear lever forward results in the gears shifting up (1-2-3-4-5) and moving/pushing the gear lever backwards results in the gears shifting down (5-4-3-2-1).

Choosing R mode puts the gearbox in reverse and N mode is neutral, wherein the engine and gearbox are disconnected. A semi-automatic gearbox doesn’t have the P (parking) mode. Therefore, the driver will have to put the gearbox in N after coming to a halt, and then engage the parking brake manually as he or she would do in case of a manual gearbox equipped car.

What’s the difference between a semi-automatic gearbox and a fully automatic gearbox?

In a semi-automatic gearbox, the driver has to shift the gears manually and only the clutch is an automatic affair. In a fully automatic gearbox, both gear shifting and the clutch actuation happen automatically through a process governed by the ECU and an array of sensors.

What are the advantages of a semi-automatic gearbox?

• Traditional automatic gearboxes (torque converters) are heavy. A semi-automatic gearbox, by automating only the clutch, is a much lighter design. A lower weight means better fuel efficiency right from the word go.
• Since the gear shifting is done manually in a semi-automatic gearbox, the power loss/lag in response is minimal.
• Semi-automatic gearboxes, in many cases are quicker than manual gearboxes due to the ECU controlled automatic clutch, a reason why they were first deployed on race cars around the globe before making it to mass production cars.
• The semi-automatic gearbox allows the driver to have a greater control over gear shifting than automatic gearbox, whose modern examples automatically shift to a higher gear once a certain rpm is achieved.
• Since the only automatic part of a semi-automatic gearbox involves the clutch, it is less expensive than an automatic gearbox.

What are the disadvantages of a semi-automatic gearbox?

• The gearbox is not fully automatic.
• The driver needs to manually deploy the parking brake.

With the Maruti Suzuki Celerio all set to kick start the trend of semi-automatic gearboxes in the Indian car market, expect more cars to follow suit in future due to the inherent advantages of such a feature, especially in traffic infested Indian roads that necessitate the frequent use of the clutch in manual gearbox equipped cars. Maruti Suzuki is said to have earmarked a production facility for semi-automatic gearboxes at its Manesar factory, which also means that the gearbox is built in India, a factor likely to result in cost-effectiveness.

CarToq Trivia: Apart from the Celerio, another small car to use the semi-automatic gearbox is the Volkswagen Up! hatchback. Also, Mahindra is said to be developing a semi-automatic gearbox for use in its products such as the Quanto and the upcoming S101 mini SUV.