In February this year, Volkswagen India had introduced to the market a mild facelift variant of the Jetta sedan. Auto Tech Review had reviewed the vehicle in details in our March 2015 edition, details of which can be found here. At that point in time though, we could drive only the manual transmission-equipped petrol and diesel variants. Recently, we reviewed the DSG-fitted TDI variant of the Jetta, and our focus particularly was on the DSG unit. Here are our impressions.
Engine & Transmission
As was mentioned in our previous report, the engines in the new Jetta are unchanged and power output for both diesel and petrol units remain the same – the 1.4 l TSI engine produces about 120 hp, while the 2 l TDI unit produce 140 hp.
The strongest characteristic of the 2 l TDI engine is its low-end power, which in combination with the double-shift gearbox (DSG) also makes it very efficient. The engine is not very quiet, but that would not count as a negative feature by any measure. Maximum torque of 320 Nm is available in the rev band of 1,750 and 2,500 rpm, and this provides short bursts of quick acceleration.
One inevitable comparison, while driving the Jetta TDI was about its Czech cousin, the Skoda Octavia. Owing to the modular MQB platform it has been built on, the Octavia is lighter that the VW Jetta, and the first thought was about the drive feel. The Jetta, built on the previous-generation PQ35 platform, might seem a little underpowered to some, but from all practical purposes, it feels and behaves the same. It must also be noted that the MQB platform allows Skoda to use the Volkswagen group's new-generation of engines.
We mostly drove the car within the limits of the capital metropolis, and as a regular executive sedan, the Jetta didn't disappoint.
The highlight of the drive, however, is the six-speed DSG unit, which in essence is a dual-clutch transmission. More on that in the next section of this report. In terms of weight, the Jetta with the DSG weighs 38 kg more than the diesel manual. We were very pleased with the smoothness of the DSG unit, and the effortless manner in which it helps the Jetta TDI move. Whenever necessary during the drive, downshifts are extremely quick as well.
Against the company-claimed fuel efficiency figure of 16.96 km/l for the DSG, we could manage about 11 km/l, as indicated by the on-board system.
DSG Dual-Clutch Gearbox
It was in 2002 that Volkswagen first presented the first duel-clutch gearbox intended for series production, the six-speed DSG, or direct-shift gearbox, codenamed DQ250. Compared to a conventional automatic transmission, the dual-clutch principle is claimed to ensure higher efficiency and lower fuel consumption and offer greater comfort and driving pleasure.
The DSG gearboxes essentially comprise of two independent gearbox units. Moving through the gears, the dual-clutch mechanism allows the engine to engage with each of the two gearboxes in turn via two drive shafts. There is a compact mechatronic module – consisting of an electronic control unit, various sensors and hydraulic control elements – that controls the gearbox. This module helps instantaneous shifts to happen between the two clutches.
In a typical dual-clutch gearbox, the odd and even gears are separated on individual shafts – so, gears 1, 3, 5 are on one clutch and 2, 4 and 6 on the other. The outer clutch has a larger diameter and is connected to the odd gears. This helps the outer clutch to handle more strain from the engine. Both the clutches run in an oil bath. The concept is that whichever gear one wants to go to – up or down – it is available on the other clutch. The DSG unit features two modes: normal and sports, with the DSG holding on to the gears for longer. In the sports mode, even the downward shifts are faster.
The mild facelift only adds to the timeless design of the Jetta, be it on the outside or the interiors. We had enjoyed driving the manual variants in February, and the DSG only accentuates the drive quality of the Jetta. The suspension is well-tuned, and overall the Jetta delivers well on the handling parameters. Moreover, it offers an all-round safety package with six airbags, ABS + EBD, ESP, EDL and more. It also has a 5-star NCAP rating to boast of.
We, however, feel DSG should be offered in all the variants, and not just the diesel's Highline variant. The next-generation Jetta, which will be based on the MQB platform, might offer that and a lot more.
Text: Deepangshu Dev Sarmah
Photo: Bharat Bhushan Upadhyay