Where electrification was the headline earlier, the onus is on manufacturers to improve combustion being better than it ever was. The diesel engine is something, Bosch say, that can be improved even further, to the tune of 10 per cent. That means slightly more power, yes, but with much higher fuel efficiency and cleaner emissions. New-generation injection systems use pressures as high as 2,500 bar in diesel engines as advanced as they can be today. Yet the potential for a cleaner solution, half a per cent at a time, presents itself as you read this. It’s constant evolution, and that’s what the focus is on.
Unlike common sense, common-rail injection systems are quite common. Present regulations almost mandate direct injection with controlled pressures to ensure compliant emissions from diesel engines. Where it was the domain of the large saloon a decade ago, sub-compact hatchbacks have it today. At our disposal were four unique examples. The most advanced were, of course, the two VW Group offerings: the Audi SQ7, with its triple-turbo 4.0-litre V8 making 435 PS and 900 Nm (the latter from 1,000 rpm), and the Panamera 4S Diesel, which uses the same engine with a bi-turbo setup for 422 PS and 850 Nm, the latter also from 1,000 rpm. Both run Bosch common-rail at a pressure of 2,500 bar — significantly higher than their previous generation models. These models also use advanced piezo-injection systems.
The next, running the common-rail system with 2,000 bar together with solenoid injection systems in their four-cylinder engines, were the Volkswagen Passat and the all-new Alfa Romeo Stelvio. The new Passat, with its 190-PS 2.0-litre engine, feels substantially more refined and responsive than its predecessor. The Stelvio is Alfa’s first SUV and uses the popular 2.2 JTD motor with 180 PS. For its size, it still manages to feel exciting, even being a diesel, with all the elements to set the Alfa apart making their presence felt — such as the start button on the steering wheel.
Not to be left behind, another avenue for alternative propulsion is compressed natural gas (CNG). It makes for a cleaner alternative to conventional fuel, albeit while using the combustion engine only slightly adapted. Being widely considered as the cleanest fossil fuel, CNG is known to produce almost half the hydrocarbons as well as considerably lower carbon dioxide emissions when compared to petrol or diesel.
The Audi A5 Sportback 2.0 g-tron I drove is a model specifically adapted using quite a few fuel management systems from Bosch. There isn’t anything really to tell it apart from its conventionally-powered counterpart, save for the second fuel-gauge display on the left in green. Even to drive, it feels no different. The 2.0-litre four-cylinder engine puts out slightly less when running on CNG, with 170 PS and 270 Nm of torque. Even so, acceleration is brisk enough and, together with its sleek proportions, the A5 makes for a good, comfortable, sensible, and clean car for city and touring use alike.
The next rational step towards clean energy comes from electrified powertrains. Bosch hope to make the experience as streamlined as possible with a gradual shift from entirely fossil-fuelled vehicles to part-electrified or hybrid vehicles and even fully electric vehicles in the near future. Autonomous driving remains the key to solving the traffic problem which plagues every major global city. However, the solution isn’t merely switching to autonomous vehicles; it’s primarily about reducing the number of vehicles on the road, and that means car sharing, something possible today, but an idea that needs to be elaborated upon considerably in terms of implementation. Until then, car-pooling in electric cars, recharged using solar or wind energy, is the best way forward to ensure we don’t eradicate ourselves.
Not that there aren’t some cutting-edge energy management solutions available today. The advent of 48-volt electrical systems presents a credible solution to many challenges shelved earlier without any feasible means of making them a reality. There are more complex systems that can be employed in cars, making them far more efficient and reliable while reducing the load on the conventional 12-volt electrical system that will continue to run in parallel for more traditional support functions not requiring more potent electronic management.
Innovations such as start/stop were only the beginning. The coasting function, eClutch, and engine management systems have now been given a boost with more advanced electrification possibilities. For a first-hand approach, the new Volkswagen Golf TSI 48V Hybrid was present. With an aim to further fuel efficiency, the rate of optimisation is staggering. Every little detail is under an electronic microscope, with control units analysing every inkling of potential fuel saving and range extension.
Another evolution which we managed to sample was the Audi A3 TFSI 48V Hybrid eClutch. Having driven the A3 eClutch the last time around, the new one presented a mega opportunity to see how much more has changed. For starters, where I needed to use the clutch pedal to get going the last time, this time I just had to select a gear and go. The system automatically recognises the speed and driver input and delivers just the right amount of juice to keep going at that pace. The coast function is also evident as it uses electric power to keep you going with the engine a silent bystander waiting to be called upon. The number of times (76!) the eClutch decoupled and recoupled the powertrain the last time astounded me. This time, I was sure it would be just as much or even more. Where the last A3 was more reactive, this one felt more predictive, and is a huge step forward towards the ultimate goal in that sense.
Of course, efficiency can envelope a broader spectrum of automobiles and there is no reason why large luxury cars cannot be more efficient. Case in point: the new Mercedes-Benz E 350 e. With a frugal 2.0-litre turbo-petrol engine and a 65-kW electric motor, the combined 286 PS and 550 Nm is enough for the two-tonne luxury saloon to get wherever it needs to in a hurry, without being inefficient.
What is electrification without the purists? By purists, I’m talking about all-electric cars. One, a proper set-for-production compact hatchback made with lightweight material; the other, a more utilityoriented creation that will replace the Deutsche Post delivery vans over time. The first is the e.GO.
Made for city use, the e.GO offers adequate performance with reasonable range. It’s set for series production in 2018. Powered by Bosch’s 48-volt electrical system and a 14.4-kWh battery pack, it allows for a 5.7-second dash from 0-50 km/h and a range of 130 km. At 3.35 metres long, it offered enough room for four, and the 650-kg weight means it won’t be too taxing on the battery either.
The Streetscooter, on the other hand, is made especially for the German postal service. It can get up to 120 km/h and has a range of 80 km. The required range is just between 50 and 60 km. More importantly, the life of the battery is 16 years.
The eAxle electric axle drive system from Bosch provides electric drive solutions across a modular, scalable platform to suit various applications. Ideal for city or highway use, the eAxle combines drive and transmission functionality together with cutting-edge Bosch mobility solutions into one compact package. It is available in a range of outputs from 50 kW (68 PS) to 300 kW (408 PS).
Battery technology is a critical aspect of future technology implementation. At present, the range and more potent abilities of systems are limited only by capacity. What is needed is more charge in a smaller area at a lower cost. Bosch are researching battery technology that will make it possible to drive longer distances without recharging, and will also cost less than current batteries. Ten years from now, Bosch expect about 15 per cent of all new vehicles worldwide to have an electric powertrain. With this in mind, Bosch are investing €400 million (Rs 3,000 crore) a year in electro-mobility.
Today’s lithium-ion batteries are superior in this respect, storing more than three times the amount of energy per kilogram. At a weight of 230 kg, the battery of a modern-day electric car provides approximately 18 to 30 kWh. To achieve the desired 50 kWh, a battery weighing up to 600 kg would be necessary. This isn’t really feasible in a compact vehicle, which is why the target is 190 kg, with a target charge time of 15 minutes for 75 per cent capacity.
The future lies in solid-state batteries, or post-lithium technology. While the technological awareness may be present, it is still in the research and predevelopment stage.
48-volt electrical system opens new realms of possibilities
Bosch eAxle is both modular and scalable ( Left) Varied range of use for the eAxle