Tuesday, February 24, 2009

Volvo - Regenerative Charging



Volvo Cars is presenting seven new DRIVe models across its full range at the upcoming Geneva auto show, three of which are equipped with a start/stop system and regenerative charging. Volvo introduced its first three DRIVEe branded models—indicating uprated environmental properties—at the 2008 Paris motor show.

All the new DRIVe models are equipped with a conventional diesel engine and manual gearbox optimized for extra-low fuel consumption. These cars are also tailored specifically for low rolling resistance and reduced air drag.

Our dedicated focus on the DRIVe models in 2009 demonstrates Volvo Cars’ ability to quickly respond to customers’ increasing demands for products with low fuel consumption and low environmental impact. At the Paris motor show in 2008, we began our broad-based launch of the DRIVe models via the C30, S40 and V50. Now both the market and we are ready to step up to the next stage

—Stephen Odell, President and CEO of Volvo Cars

The Volvo Cars DRIVe range is divided into three categories linked to three emission levels: 120, 140, and 160 gCO2/km.

DRIVe performance, CO2 emissions and fuel consumption
ModelEnginePower/TorqueCO2Fuel consumption
C30 Start/Stop 1.6D 109 hp/240 Nm 104 g/km 3.9 L/100km
S40 Start/Stop 1.6D 109 hp/240 Nm 107 g/km 4.0 L/100km
V50 Start/Stop 1.6D 109 hp/240 Nm 107 g/km 4.0 L/100km
V70 1.6D 109 hp/240 Nm 129 g/km 4.9 L/100km
S80 1.6D 109 hp/240 Nm 129 g/km 4.9 L/100km
XC60 2.4D 175 hp/420 Nm 159 g/km 6.0 L/100km
XC70 2.4D 175 hp/420 Nm 159 g/km 6.0 L/100km

120 g level. As of spring 2009, the Volvo C30, S40 and V50 1.6D DRIVe will be offered with a Start/Stop function. The 1.6D delivers 109 hp (81 kW) of power and 240 Nm (177 lb-ft) of torque. This helps lower emissions to 104 gCO2/km for the Volvo C30 and 107 gCO2/km for the S40 and the V50 family estate model. The C30 thus also meets the lowest eco-tax levels (105 g) in Europe.

In order to reduce carbon dioxide emissions to such an extent, the new DRIVe versions of the C30, S40 and V50 have been equipped with two intelligent new features. One is a Start/Stop function that allows the engine to switch off when the car is at a standstill, for instance while waiting at traffic lights or when stuck in traffic queues.

If the driver puts the gear lever into neutral and releases the clutch while at a standstill, the engine switches off. The next time the driver presses the clutch, the engine starts up again. This technology can reduce fuel consumption and thus carbon dioxide emissions by 4-5% in mixed driving conditions. Start/Stop technology is particularly effective in urban traffic, when the saving may be as much as 8%.

While the car is at a standstill and the engine is switched off, some electronic systems such as the air conditioning step down to standby level in order to save fuel. However, the Start/Stop system continuously monitors the comfort level and automatically reactivates the relevant systems if for instance the temperature increases in the passenger compartment. The system does not set any limits for comfort-enhancing features such as the sound system or other facilities that the customer wants to maintain.

This monitoring system, which is specific to Volvo Cars, and the resultant high comfort level have been made possible owing to an additional small battery that supports the larger battery by providing extra power. Thanks to this extra battery, Volvo’s DRIVe models also feature particularly quick and smooth start-up and the audio system, for instance, remains totally unaffected when the starter motor is activated. The standard larger battery has been upgraded to handle up to 175,000 Start/Stop cycles.

The driver continuously receives feedback about system status via the in-car information display. The Start/Stop function can be engaged and disengaged via a special DRIVe button in the centre console. In the default setting, the function is activated. In the future, this special DRIVe button will also regulate additional systems such as the DRIVe “economy settings” for particularly fuel-efficient performance that are on the way in forthcoming models.

The other new feature in the C30, S40 and V50 DRIVe 1.6D with Start/Stop is a regenerative charge facility. This is a function that charges the battery as soon as the driver releases the accelerator or brakes while a gear is engaged. By harnessing the car’s kinetic energy, the alternator does not have to use diesel fuel as a power source when the battery’s charge level dips. Fuel savings of between 2 and 3% can be achieved with this function.

140 g level. The Volvo V70 and S80 are now also being offered in DRIVe versions. The cars are equipped with the same powertrain—1.6-liter diesel engine and manual gearbox—as the smaller models but with specially tailored engine software and different ratios in third, fourth and fifth gears.

The optimized powertrain is a major aid in helping Volvo’s larger sedans and family cars cut their fuel consumption and CO2 emissions. The V70 and S80 are down to 4.9 l/100 km (48 mpg US) and 129 g, an improvement of 18% and 15%, respectively, compared with the current two-liter diesel.

Other factors also contribute to the reduction in fuel consumption, including low rolling resistance tires, and and an electric power steering pump.

  • Covered grill
  • Lowered chassis (20 mm front, 15 mm rear)

160 g level. For model year 2010, the powertrain range for the new Volvo XC60 crossover and the XC70 adventure estate will expand with a front-wheel drive DRIVe version powered by the 2.4D engine. The 2.4D delivers 175 hp (130 kW) of power and 420 Nm (310 lb-ft) of torque. CO2 emissions will be 159 g/km with fuel consumption of 6.0 L/100 km (39 mpg US) for both cars.

In addition to front-wheel drive, a number of minor improvements all help deliver the new model’s competitive fuel consumption and CO2 figures. Volvo Cars’ engineers succeeded in reducing friction and pump losses in the diesel engine and in cutting the pressure drop in the intake and exhaust systems.

Injection pressure has increased with the latest generation of high-pressure pumps and the injection architecture has been refined with the help of a piezo-electric system. The engine now has lower compression, more efficient combustion and the latest generation of engine management software. The turbocharger has been optimized to deliver high torque from low revs.

The gear ratios have been optimized so the car can be driven economically. For instance, when driving at 100 km/h in top gear, engine revs and thus also fuel consumption are lower with the new powertrain.

The fuel-reduction measures of these cars will also benefit the rest of the range. Also, all the current automatic transmissions will be 5-7% more efficient in forthcoming versions within the coming two years.