Re-introducing E-motion: Half the cylinders, double the driving pleasure.
For several years, VLT has provided the world with the best compromise between consumption and driving pleasure through its range of E-Motion engines; diesel and petrol engines with minimal displacement, maximum capacity. Today, VLT presents an expansion to the E-Motion range by offering E-Motion DUAL; half the cylinders, double the driving pleasure.
The basis of the E-Motion DUAL system is a newly engineered family of three- and four-cylinder engines which closely rely on TCi technology to provide maximum power at minimal displacement.
TCi technology is designed to develop maximum horsepower from a smaller engine, through the principle of turbocharging. Equipped with a variable geometry turbocharger, the engines can provide the best possible power output over a very wide rpm range, meaning that the engine is easier to drive and will perform better in a variety of circumstances.
The engine is connected to a 9-speed VLT A94 automatic transmission, which will provide the perfect combination between comfort, economy and performance, especially due to its ability to be configured in various drive modes, which affect the gearshifting behaviour of the gearbox. The gearbox is as standard connected to both a shifter in the center console and paddle shifters on the steering wheel; the driver may choose to use either.
The most important new function of the E-Motion DUAL system is however an electric motor, wedged between the engine and gearbox. Depending on the version, the DC electric motor provides as much as 74 kW (100 PS), and will always provide drive to the wheels. The specific setup of the system means that the electric motor is completely able to move the car by itself, and depending on the battery pack, this results in a fully electric range of 30-50 km. After this, the internal combustion engine will automatically start in order to reinforce the electric engine. The internal combustion engine will also be started in case a lot of power is suddenly demanded from the driveline, or when the car exceeds the maximum speed of the fully electric mode, which is 120 km/h (75mph). In order to make sure that the combustion engine is able to start as quickly as possible, a belt will rapidly initiate the starter engine, and subsequently bring the engine to the right rpm range, allowing the combustion engine to join in with the electric engine seamlessly. The drive-by-wire pedals are able to sense the pedal pressure exerted, thus making the car able to prepare the combustion engine for its task, even when its services are not required yet.
Depending on the VLT model the DUAL system is implemented in, there is a lithium-ion battery pack to power the electric motor located either under the floor of the passenger compartment or above the rear axle, below the boot. This battery pack can provide as much as 15 kWh, depending on the model. Nominally, this should be enough to allow a range of 30-50 km, depending on the driving conditions and the style of driving. The battery pack is normally recharged by plugging it in to a charging station or a wall outlet, with the charging system onboard the DUAL system capable of handling as much as 135 kW of charge being applied at any one time, enough to recharge the battery pack in less than 10 minutes. When plugged in to a regular 230 V 2.3 kW power outlet, the battery pack can recharge itself in around 6 to 7 hours. To improve power consumption, the DUAL system makes use of regenerative braking (in which power is fed back into the battery pack when slowing down), which can be regulated in strength; brake regeneration can be switched off entirely, or at the other extreme, it can be set so powerful that letting go of the throttle will automatically induce energy regeneration and braking, thus allowing for 1-pedal driving. Furthermore, the combustion engine will slowly recharge the electric engine as it is used, unless the battery pack is fully charged.
This makes the DUAL system a remarkably fuel efficient system, whilst also allowing for highly potent drivelines. A VLT L5 DUAL-D, fitted with a 225 PS 2-litre Diesel engine and a 60 kW (82 PS) electric engine, can attain a fuel consumption of less than 3l/100 km or 78 MPG whilst providing a combined power rating of 280 PS, the power commonly provided by a performance 6-cylinder engine.
DUAL drivelines will first be introduced on the new VLT L5, coming Q2 2014, together with a line of new TCi and TCD which will also feature as the combustion engines in the E-Motion DUAL systems. From there on, the new L3 and L2 models (expected Q3/4 2014) will also feature DUAL drivelines, with the L6, L7 and S/X model ranges being updated later.
Kaija Ulander
Sara Ulric
