Renault Scenic Showcases Getrag DCT
French automaker Renault has become the third major car producer – after Volkswagen and Ford – to bring dual clutch transmissions to market as a mainstream automatic. From this summer one of the most popular engine choices within the Mégane platform family – the 1.5 liter DCi diesel – has gained an automatic option in the shape of Getrag’s 6DCT250 dry-clutch DCT. This is the lead application for this new transmission, though related versions are in production in North America by the Getrag-Ford joint venture and are being fitted to gasoline versions of the Fiesta and, next year, Focus sold in the region.
Renault labels its DCT option EDC, for efficient dual clutch, and in its initial launch strategy the transmission is presented as a simple automatic option that happens to improve efficiency and cut fuel consumption – in addition to the standard automatic advantages of smoothness and convenience. No effort is made to give EDC a dynamic or sporty dimension, though Renault says that this may come with later models and engines.
The Mégane family encompasses a wide range of models, from the sporty three-door coupé and five door hatchback to a station wagon and a classy cabriolet with a metal folding hardtop; a very important member of the family is the Scenic, the medium-sized minivan that was a sensational segment-buster in the 1990s and which created a large and profitable new market for Renault. The third-generation Scenic, launched in 2009, is available in standard and Grand wheelbase versions, seating five and seven respectively.
The Scenic, especially in its 4.5-meter long Grand incarnation, seems a very large and substantial vehicle for a diesel of just 1.5 liters and 110 horsepower. It is tall and long and provides sumptuous accommodation for its passengers, yet in combination with the new dual clutch transmission the small diesel is an effective engine choice, making particularly good use of the turbo unit’s 240 Nm torque and, crucially, trimming CO2 emissions from the already good 136 g/km of the six-speed manual to just 130 g/km.
Keyless operation means the diesel engine is started (and stopped) via a button on the dashboard; it has a quiet and regular idle and, with the center transmission lever slotted backwards in to the Drive position, initial pullaway from rest is smooth and easy to control. Driven gently at lower speeds, the EDC system is straightforward and unobtrusive, responding just like a familiar torque converter automatic with almost imperceptible upshifts and the engine revs keeping low for maximum efficiency and minimum noise. A particularly good feature of the set-up is the way that, unlike most other transmissions, it makes excellent use of the diesel’s low-down torque by allowing the driver to use wide throttle openings at low engine rpm when climbing hills; most other transmissions would be programmed to kick down to a lower and noisier gear under such circumstances. Peak torque is at 2000 rpm but this feature allows the engine to perform effectively, and without any driveline vibration, from 1500 rpm upwards.
Confusingly, the semicircular rev counter in the entirely electronic instrument display is red-lined at 6000 rpm, even though the diesel reaches peak power at 4000 rpm and on full throttle the transmission shifts up shortly after this point. In truth, full throttle and high engine speeds are not the most important ingredients in the Scenic’s smooth and steady character. Upshifts, even when driving with some urgency, are always a smooth blurring between one ratio and the next, in contrast to sportier transmissions where the gear can slot in with a noticeable jolt. However, when kickdown is needed for a quick overtaking maneuver, the transmission’s response is not as fast as that of a sporty DCT or planetary automatic. A gentle squeeze of the throttle is all that’s needed to trigger a single downshift, say from fifth to fourth, but when full acceleration is required from, say, a 70 km/h, sixth gear cruise, there is a noticeable hesitation as the gearbox shifts down several ratios. This drawback could pass unnoticed by many drivers, but would be an irritation to those in a hurry on an undulating country road.
In line with Renault’s decision that the EDC is not a sports transmission option, no wheel-mounted shift paddles are provided; to override the transmission’s automatic program the driver must move the center shift lever left (even on right hand drive versions) into its manual slot, where a push forward triggers an upshift and a pull to the rear brings a downshift. This downshift facility is sometimes required for engine braking when descending steep hills: sometimes, but not always, the transmission will downshift by itself for the descent.
After an initially smooth launch from rest, there is a slight jolt at around walking pace, presumably connected with the engagement of second gear, and, though low-speed creep in traffic queues is almost as smooth as with a torque converter automatic, the driver can initially be surprised by an occasionally unprogressive drive take-up in forward and reverse maneuvering. With greater experience of the vehicle, however, this is soon compensated for and mastered.
In contrast to some of its competitors, Renault has not opted for a flat walk-through floor and an electronic dash-mounted transmission selector lever. This gives the advantage of a spacious center console for storage of drinks, phones and other travel paraphernalia, complementing the design’s already outstanding practicality. The central instrument panel is especially clear, with a graphic bird-view map display and large figures for its speedometer; many of the most important controls, such as those for the stereo system, are clustered on or around the steering wheel, making for easy fingertip control without any need to take attention away from the road ahead. Add to this a smooth ride, a capable chassis and quick, positive steering, and it is clear that the Scenic is a much more satisfying long-distance vehicle than its European soccer-mom image would have one believe.
| Renault Scenic 1.5 Dynamique EDC | |
|---|---|
| Engine | 1461 cc four-cylinder, 8 valves |
| Induction | Diesel turbo |
| Max Power | 110 hp at 4000 rev/min |
| Peak Torque | 240 Nm at 2000 rev/min |
| Transmission | Getrag 6DCT250 six-speed dry clutch DCT |
| Maximum Speed | 180 km/h |
| 0-100 km/h Acceleration | 13.4 sec |
| CO2 Emissions | 130 g/km |
| Price (approx) | £20,425 ($28,545) |
Story Filed: 11/17/2010
By Tony Lewin, managing editor DCTfacts.com