GaN Systems to present paper on application of SPICE models for high-power GaN elements in automotive applications
AeroVironment introduces TurboCord compact 240V/120V portable charger

Mercedes-Benz unveils the new V-Class MPVs; full-size luxury diesel MPV with fuel economy up to 41.3 mpg

Launch of the V-Class. Click to enlarge.

Mercedes-Benz unveiled the new V-Class full-size MPVs at an event in Munich. The V-Class, the successor to the Viano, is the newest and largest member of the Mercedes-Benz passenger car family. The new V-Class is equipped with four-cylinder diesel engines, offering fuel consumption as low as 5.7 l/100 km (41.3 mpgUS), or 149 g CO2/km, in the V220 CDI model.

The 2.1-liter turbodiesel engine for the V-Class offers three power output levels: 100 kW (136 hp), 120 kW (163 hp) and 140 kW (190 hp). Internally designated OM 651, the engine, which has proven itself in almost all car models of the brand from the A-Class to the S-Class, has been further developed specifically for use in the V-Class. The focus of these efforts was to combine the performance of a six-cylinder engine with the efficiency of a four-cylinder.

“With the new V-Class we are expanding the Mercedes-Benz premium passenger car range with a saloon for up to eight people.”
—Dr. Dieter Zetsche, Chairman of the Board of Management Daimler AG and Head of Mercedes-Benz Cars Division

The top-of-the-range model V 250 BlueTEC has a torque curve and power delivery on a par with the current 3-liter V6 turbodiesel, but consumes up to 28% less fuel and complies with the Euro 6 emissions standard.

Mercedes-Benz achieved this through numerous measures such as fourth-generation common-rail injection; a switchable water pump; an on-demand oil pump; and two-stage turbocharging.

For the variants with 7G-TRONIC PLUS automatic transmission, the ECO start/stop function also is a standard feature. Common characteristics of all three four-cylinder units are the durable cast iron engine block, the weight-optimised high-strength aluminium cylinder head, two overhead camshafts, the low-friction valve train with cam followers, and four valves per cylinder.

The two-stage turbocharging ensures responsive start-off ability and high peak power. The compact module for the two-stage turbocharging consists of a small high-pressure (HP) turbocharger and a large low-pressure (LP) turbocharger. These are connected in series, and each has a turbine and a compressor driven by this turbine; the optimum charge pressure can be built up at low engine speeds.

V-Class engine range
  V 200 CDI V 220 CDI V 250 BlueTEC
Cylinders 4 in-line 4 in-line 4 in-line
Displacement [cc] 2143 2143 2143
Rated output [kW/hp @ rpm] 100/136 @ 3800 120/163 @ 3800 140/190 @ 3800
Rated torque [N·m @ rpm] 330 @ 1200-2400 380 @ 1400-2400 440 @ 1400-2400
Emission category Euro 5/III Euro 5/III Euro 6/I
Combined fuel consumption man. (auto) [l/100km] 6.1 (5.8) 5.7 (5.7) (6.0)
Combined CO2 man. (auto) [g/km] 159 (152) 149 (149) (157)
Acceleration 0-100 km/h [s] 13.8 (12.8) 11.8 (10.8) (9.1)
Top speed [km/h] 182 (181) 194 (195) (206)

The most important advantage of this concept, according to Mercedes-Benz, is the improved cylinder charge and the resultant high torque at low engine speeds. The V 200 CDI offers 300 N·m (243 lb-ft), while the V 220 CDI offers 380 N·m (280 lb-ft)—20 N·m more in each case in comparison to the predecessor.

The combined NEDC consumption of the V 200 CDI is reduced by 12% to 6.1 l/100 km. The 5.7 l/100km of the V 220 CDI represents an 18% reduction in fuel consumption.

The engine of the top-of-the-range V 250 BlueTEC delivers torque up to a maximum of 440 N·m (325 lb-ft). This is the same figure as for the 3-liter V6 diesel in the predecessor model. Fuel consumption, on the other hand, stands at 6.0 l/100 km (39 mpgUS), or 28% less than the six-cylinder engine, despite comparable performance.

The new Mercedes-Benz V-Class – V 250 BlueTEC. Click to enlarge.

If the driver activates “Sport”, “Comfort” or “Manual” transmission mode with the AGILITY SELECT switch, the characteristics of the accelerator pedal change so that the engine responds more quickly to the throttle and the maximum torque rises to 480 N·m (354 lb-ft) (“overtorque”).

The V 200 CDI and V 220 CDI models are fitted as standard with the ECO Gear 6-speed manual transmission. Its features s particularly large gear ratio spread, with a short first gear and a long sixth gear with moderate rpm level. This design makes allowance for situations such as moving off on slopes with a horse or boat trailer in tow as well as long-distance journeys on motorways.

The top-of-the-range model V 250 BlueTEC is equipped as standard with the 7G-TRONIC PLUS transmission with DIRECT SELECT lever and DIRECT SELECT steering wheel gearshift paddles. The automatic transmission is available as an optional extra for the V 200 CDI and V 220 CDI models. Owing to its seven gears, the automatic can adjust the engine speed even more precisely to suit the driver's intentions. More pulling power is available for flat-out acceleration, while during relaxed cruising the engine speed is reduced to an economical level.

The features of the latest version of the 7G-TRONIC PLUS to emerge include a new torque converter with reduced slip, an ECO shift mode with a wider ratio spread, and an auxiliary oil pump to maintain the operating pressure when the ECO start/stop function is activated. Low-friction components in conjunction with low-friction oil help to reduce the operating pressure. Another benefit to comfort: with the DIRECT SELECT lever on the steering column, drivers can set the transmission positions “P”, “N”, “R” and “D” with a light tap without taking their hands off the steering wheel.

The ECO start/stop function, a standard feature with the 7G-TRONIC PLUS automatic transmission, operates with starter-supported direct-start. This means that when the engine is switched off, the attitude of the crankshaft is registered by a new crankshaft sensor so that the engine control unit knows the positions of the individual pistons. On restarting, it can then select the cylinder that is in the most suitable position for first ignition. This ensures that the engine starts up immediately.

The ECO start/stop function is a part of the BlueEFFICIENCY package, which is standard equipment in all versions featuring the 7G-TRONIC PLUS automatic transmission and is optionally available for all variants with 6-speed manual transmission. It also comprises the on-demand fuel pump control as well as complete engine compartment and underbody panelling, which ensures turbulence-free air flow underneath the vehicle body.

As an option in combination with the 7G-TRONIC PLUS transmission, Mercedes-Benz offers the AGILITY SELECT system, which permits individualizing the driving experience. Four transmission modes vary the throttle response and shift points of the automatic transmission: “ECO” (E), “Comfort” (C), “Sport” (S) and “Manual” (M).

“Comfort” automatically is activated when the engine is started and includes a comfort-emphasizing, harmonious accelerator characteristic. The ECO start/stop function is activated. In “ECO” mode the 7G-TRONIC PLUS changes gears at particularly low revs. At the same time the output of the air conditioner, the heated rear windscreen and the seat heating is reduced. When the vehicle is stopped at a traffic light or in a tailback, the ECO start/stop function goes into action.

When the driver switches to “Sport” mode the characteristic of the accelerator pedal is changed to make the engine respond more quickly to the throttle. The automatic transmission makes use of the entire engine speed range to change gears, and shifts faster. The ECO start/stop function continues to be active. In “Manual” mode the automatic transmission can be operated by hand using the gearshift paddles on the steering wheel. This appreciably shortens the shift times compared with the Comfort and ECO modes. The ECO start/stop function is deactivated, but can be activated manually.

Mercedes-Benz Intelligent Drive. Like all Mercedes-Benz passenger cars, the new V-Class features an extensive range of safety equipment, including numerous innovative driver assistance systems based on radar, camera and ultrasonic sensors, first introduced under the name “Mercedes-Benz Intelligent Drive” in the new E-Class and S-Class. These reduce the risk of hazards such as strong crosswind gusts, the blind spot or insufficient distance to other vehicles to an absolute minimum.

The new full size MPV is equipped as standard with ATTENTION ASSIST, which can warn against inattention and drowsiness, and Crosswind Assist. With a relatively large and long side area compared with other passenger car models, full size MPVs are more susceptible to the effects of strong crosswinds. Crosswind Assist counters these effects to protect those inside the new eight-seater V-Class. It assists the driver and can compensate for the effects of wind by applying the brakes on the front and rear wheels on the side of the vehicle facing the wind. Further assistance systems are available as optional extras. Like Crosswind Assist, most of these are available in this segment for the first time.

Active Parking Assist enables automated parking with active steering and brake intervention in both parallel and perpendicular parking spaces. It is an enhanced version of the PARKTRONIC system with Parking Guidance. The system is also able to maneuver the vehicle out of parallel parking spaces all by itself with automatic steering and brake control, assuming the vehicle was parked there automatically previously.

A 360° camera can be set to switch on automatically when reverse gear is engaged. Four networked short-range cameras are used to provide a bird’s-eye view of the V-Class on the central display, allowing a realistic all-round view when parking and maneuvering. Consequently, even obstacles located below the window line of the V-Class and outside the driver’s range of vision can be detected. This helps when approaching curbs, for example.

One camera is mounted centrally at the front end in the radiator grille, plus there is one camera in each of the exterior mirrors and a further camera in the tailgate handle. The virtual viewpoint calculated based on the camera images covers an area of around 3 metres ahead of and behind the vehicle and 2.5 meters on either side of the vehicle.

The display can show various views in addition to the bird’s-eye view, including PARKTRONIC information, additional guide lines and steering lines to make maneuvering easier, and the vehicle's range of movement when the driver turns the steering wheel. If a trailer coupling is fitted, there is also a special view available when reverse gear is engaged to make it easier to manoeuvre the ball head up to the drawbar.

With two short-range sensors in the rear bumper, the radar-based Blind Spot Assist can detect vehicles in the driver’s blind spot—when changing lanes or overtaking, for example. In such situations, the system gives the driver an audible and visual warning. The warning zone (blind spot) starts near the B-pillar and extends around 3.5 metres to either side of the V-Class and 3 metres beyond the back of the vehicle. The system is activated when the speed reaches 30 km/h (18.6 mph).

The V-Class offers a further new feature in this segment with the radar-based collision warning system with adaptive Brake Assist, which reduces the risk of rear-end collisions. At speeds above 7 km/h (4.3 mph), the COLLISION PREVENTION ASSIST sensor system monitors the traffic area ahead of the vehicle—the distance to a stationary obstacle in the direction of travel up to a speed of 70 km/h (43 mph), and the distance and speed of approach to vehicles in front up to a speed of 200 km/h (124 mph).

If there is a risk of a collision with moving or stopping vehicles, COLLISION PREVENTION ASSIST gives the driver a visual and audible warning, and calculates the braking power required to avert the collision in the best-case scenario. Braking is initiated at the moment the driver of the V-Class clearly presses the brake pedal.

The DISTRONIC PLUS adaptive cruise control system in the V-Class is the first radar-based assistance system to be offered in this segment. It makes the driver’s job easier in heavy traffic and also helps to prevent rear-end collisions. To this end, the system controls the speed at the level preselected by the driver between 0 and 200 km/h when the lane is clear. If the radar sensor system detects a slower-moving vehicle within a range of around 200 meters, DISTRONIC PLUS reduces the speed and follows the vehicle in front, maintaining the pre-programmed desired distance. The adaptive cruise control accelerates the V-Class back up to the desired speed when the driver moves into a clear lane or when the vehicle in front increases its speed and the driver follows it whilst maintaining the desired distance.

If the system detects the risk of a rear-end collision, it gives the driver a visual and audible warning, and it calculates the braking pressure required for the adaptive Brake Assist to stop the V-Class in time. This braking assistance is available as soon as the driver presses the brake pedal.

The DISTRONIC PLUS adaptive cruise control can brake the V-Class with a deceleration of up to 4 m/s² and—if required—to a standstill. The system is then reactivated when the driver either actuates the cruise control lever or briefly presses the accelerator. As DISTRONIC PLUS is a convenience system that only brakes the vehicle with moderate deceleration and also only accelerates the vehicle to a limited extent, the driver receives a visual and audible warning and is prompted to intervene if greater deceleration is required. If the driver applies the brakes following this prompt, adaptive Brake Assist (BAS) intervenes to assist the driver.

The camera-based Lane Keeping Assist can detect the risk of a vehicle leaving its lane unintentionally and warn the driver by making the steering wheel vibrate. To this end, the system evaluates the images provided by a camera positioned behind the windscreen, which monitors the lane markings. Based on these data and on the activity on the part of the driver that it registers, Lane Keeping Assist determines whether the vehicle is leaving its lane intentionally or unintentionally. The system is active at speeds between 60 and 200 km/h.

Another system Mercedes-Benz uses to help prevent accidents is Traffic Sign Assist, available in conjunction with COMAND Online. The system detects speed-limit signs and no-overtaking signs and can warn the driver if it detects no-entry signs. To do this, the camera inside the windscreen monitors the road signs, including those on overhead gantries or at road works. The image data are compared with the navigation system information and can be displayed both in the instrument cluster and on the COMAND display map view.

If the camera does not detect any speed-limit signs or if a speed limit no longer applies, the legally allowed maximum speed based on the navigation data is displayed. If a no-entry sign is detected, the system’s wrong-way warning function gives the driver a visual and audible warning—an effective way of helping to reduce serious accidents caused by “wrong-way drivers”.

At market launch in late May 2014, the new V-Class will be available as a long-wheelbase model with a length of 5140 millimeters, a wheelbase of 3200 millimeters and lengthened overhang. It will be available to order from 6 March 2014. The compact and extra-long variants will follow in due course.


The comments to this entry are closed.