Advanced petrol engine tech and the demise of the diesel
Petrol engines will not be dead by 2020. They are cheaper to build than diesels, and those savings will partially offset the cost of building a hybrid system. BMW is testing a self-ignition running mode, but also under consideration is a combined injector and multi-point laser spark plug. The target Co2 figure is 80g/km, dropping to 70g/km by 2025.
Encapsulated engine and floorplan
The engine bay of the 2020 3-series will be almost completely enclosed, with an undertray running the full length of the car to help reduce aerodynamic drag. Even the suspension arms could be cast into an aero-friendly shape to keep the airflow as smooth as possible.
Laser sensorsSensors will be used to detect other vehicles, pedestrians and cyclists. They will help guide the car in narrow motorway lanes and will be able to override the steering to prevent the car straying out of its lanes.
Production ready in the next two to three years, so by 2020 they will be mainstream. Uses a photonic process to create white light that’s 1000 times brighter, 100 times smaller and twice as efficient as LEDs.
Aerodynamic wheel housingsMuch engineering effort is going into cutting drag around the wheels and inside the wheel housings. Taking inspiration from the BMW i8, the seventh-gen 3-series is likely to use scoops to channel air across the face of wheels, creating a ‘boundary layer’ to reduce turbulence.
Low-drag brakesConventional brake pads drag on the discs, wasting energy. In future the pads will stand off the discs and use intelligent prediction to pull them up to the disc face if the driver is about to brake.
Almost completely faired in, the wheels are designed to smooth airflow. Brake cooling will mostly be handled by flow through the air scoop on the nose.
Carbonfibre partsThe battle to lose weight will still be at the forefront in 2020, not least to offset the extra heft of EV motors and their batteries. BMW’s experience in the production of carbonfibre-reinforced plastics will be well advanced by then, so there’s a good chance of carbonfibre body panels, seat frames, dashboard supports and door trims featuring.
Full head-up displayHead-up displays will become more common and more sophisticated. The Vision ED concept showed the future: layers of information, such as sat-nav directions, radio stations and alerts projected into the driver’s eye line.
Adds extra information about gradients, so the car can benefit from engine-off downhill runs and can calculate the most economical route by taking into account the extra energy needed for uphill driving.
Live car-to-car alerts
Using a built-in SIM card, the next-gen 3-series will automatically send out information about traffic and weather conditions, the latter triggered by the automatic wipers and auto headlamps activating. If the stability control system is activated, that could warn other cars of locally slippery conditions.
Touch-sensor door handles
Expensive and complex door handles could disappear on upmarket cars by 2020, replaced by a simple hollow with touch sensors and a proximity key.
Nine-speed auto with 'Sailing' modeAutomatic gearboxes can be in exactly the right gear to boost economy, and also link into other systems to engage a new ‘sailing’ mode. This works in conjunction with 3D sat-nav to shut down the engine and shift the transmission into neutral or ‘sail’ mode as the car approaches a downward slope, allowing the car to coast without using energy.
Battery packThe i3 concept shows how the future 3-series’ structure will be optimised to fit a battery pack in the rear of the car. It must accommodate either small or large batteries, the latter for a plug-in hybrid with a 25-mile-plus range. A plug-in version of the petrol engine could deliver 43g/km of CO2, falling to 37g/km by 2025.
During the production run of the seventh-gen 3-series, height-adjustable suspension, which drops down at higher speeds to cut aero drag, could become an option to improve real-world fuel economy.
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