More than two and one-half years after the car was first announced (earlier post) and more than one year after sales began in Germany and Central Europe (earlier post), the US-spec version of the Audi A3 Sportback e-tron plug-in hybrid will begin arriving in US showrooms in the next few weeks.
Although the EPA has not as of this writing released the final fuel economy numbers for the US A3 e-tron, Filip Brabec, Director, Product Management, Audi of America, said that the figures will be around 83 to 86 MPGe combined (depending on the equipment level), with 35 to 39 mpg gasoline only and 16-17 miles of EV range. The A3 e-tron can cruise at up to 80 mph in all-electric mode; a spec we confirmed—with enjoyment—last week during a media drive in the San Francisco Bay Area.
The A3 Sportback e-tron accelerates from 0-70 in a respectable 7.6 seconds—comparable to the 7.4 seconds of the 2016 A3 Cabriolet (1.8 TFSI), and faster than the currently sidelined A3 TDI (8.1 seconds), but slower than the A3 2.0T (5.9 seconds) and the very sporty S3 (4.7 seconds). Top speed for the A3 Sportback e-tron is 130 mph.
The Audi A3 Sportback e-tron is a parallel hybrid, with a drive unit comprising a modified 1.4 TFSI which develops 110 kW (150 hp) and 250 N·m (184 lb-ft) of torque; a six-speed S tronic transmission integrated with a 75 kW, 330 N·m (243 lb-ft) liquid-cooled, permanent magnet-driven electric motor; and an 8.8-kWh liquid-cooled lithium-ion battery pack packaged beneath the rear seat. System output is 204 hp (152 kW) and 258 lb-ft (350 N·m) of torque.
|Battery pack capacity vs. electric range for selected PHEVs in the US. The A3 e-tron falls into the cluster of mid-sized battery packs (7-10 kWh). Click to enlarge.|
The A3 Sportback e-tron plug-in hybrid is the first electrified Audi sold in the US, and the first step towards an electrified future for Audi here, combining the Audi premium driving experience with the efficiency of an electric motor. (Audi execs insist that this is the first of many Audi e-tron models which will come to the US—among them being the future production version of the very compelling e-tron quattro (earlier post), which was designed with the US market in mind and with US participation, said Brabec.)
The car is tightly engineered, and drives, as one would expect, like an Audi. The front suspension is a MacPherson strut design with A-arms and aluminum pivot bearings, joined to an aluminum subframe. The electromechanically assisted steering system operates together with various assistance systems, while reducing mechanical drag for greater efficiency.
In the four-link rear suspension, which utilizes a steel cross member, the springs and shock absorbers are mounted separately. The electronic stability control (ESC) also includes an electronic differential lock and secondary collision brake assist. When driving through curves, it can brake the inside front wheel very slightly to help minimize understeer and improve traction.
As a result, steering is light, and higher-speed cornering is firm, without any wallowing from the extra weight of the battery pack in the rear. On a drive along tightly winding, climbing and descending, and sometimes narrow roads, the A3 Sportback e-tron stayed planted to the pavement on its line through tight curves taken at speed.
One of the more striking driving characteristics of the A3 Sportback e-tron is the remarkably seamless transition between the motor and the engine...seamless to the point of not being detectable aside from the engine sound. Audi engineers achieved this through the design of the drive unit itself, and through the control software.
The drive unit. The disc-shaped electric motor is integrated into the six-speed e-S tronic, which transfers the power to the front wheels. The two powerplants complement each other. The electric motor develops peak torque from start to around 2,000 rpm, and the TFSI’s maximum pulling power is available in a range from 1,750 to 4,000 rpm.
|Top: transverse-mounted drive unit. Bottom: major components. Click to enlarge.|
One of the biggest engineering efforts that we put inside this car has to do with the transition of the electric into combustion and back. That was very key to us to make sure that it is not jerky and doesn’t have any kind of compromises.
Just to give an example. When we start the engine with the electric motor, we increase the output of the electric motor to accomodate starting the engine. We have a clutch that engages and connects the two, that gets the engine going. Once the oil pressure builds up to a sufficient level, we run the engine at zero load, at which point we disconnect the two again. Once the engine catches up with the right speed with the electric motor, we engage again. That’s how we make sure the transition is very very smooth throughout.—Filip Brabec
|Further detail on the e-motor and clutch system. Click to enlarge.|
The four-cylinder engine is equipped with a turbocharger with an electric bypass and a thermal management system which uses a high-performance coolant pump module. Its heart is the exhaust manifold integrated into the cylinder head. It quickly warms up the engine following a cold start, and at high load the water jacket reduces the temperature of the exhaust gas. The coolant loop for the TFSI also incorporates the oil cooler for the S tronic.
The hybrid concept of the A3 Sportback e-tron often does not activate the combustion engine until kickdown, even when cold. The A3 Sportback e-tron therefore includes special protective features, such as coated piston rings and bearings.
The electric motor is a permanently excited synchronous machine. It weighs 34 kilograms (75.0 lb) and is liquid-cooled via a cooling jacket in the stator. The electric motor is located behind the engine’s dual-mass flywheel and includes a decoupler. When the combustion engine starts, it is tow-started by the electric motor via the clutch. Once its reaches the same speed as the electric motor, the clutch closes. This happens smoothly, as noted above, within a few tenths of a second.
The dual-clutch transmission features a three-shaft layout. Its two subsidiary transmissions are served by the multi-plate clutches K1 and K2, which are immediately downstream of the decoupler K0. (See diagram above.) Gears are shifted by switching the clutches. This takes just a few hundredths of a second and occurs with no detectable interruption of propulsive power.
Battery pack. The voltage of the 8.8 kWh battery pack ranges between 280 and 390 volts, depending upon level of charge. The battery comprises 96 prismatic cells—currently from Sanyo—arranged into eight modules of twelve cells each. Including the battery management controller and the battery junction box for the connections, the battery system weighs 125 kilograms (275.6 lb). The bottom shell of its housing is made of diecast aluminum, the top shell of polymer.
|Structure of the battery pack. Click to enlarge.|
The high-voltage battery has an ideal operating temperature of around 25 ˚C (77 ˚F). It therefore has a liquid cooling system in which four cooling plates regulate the temperature of the eight modules. Cooling is by means of a separate, flexibly controlled low-temperature loop, which also includes the power electronics and charger, as necessary. The Audi A3 Sportback e-tron can generally also be driven solely on electric power in the heat of mid-summer and the below-freezing temperatures of winter.
|Top: The battery cooling loop. Bottom: Detail on the chiller. Click to enlarge.|
Installed under the rear seat, the flat battery is extremely well protected in an area where the high-strength and ultra-high-strength steel components of the occupant cell form an especially strong structure. The housing is bolted to the vehicle floor at five points. In the event of a crash sufficiently severe to trigger the belt tensioners or airbags, the system is disconnected from the power supply.
The 12-volt battery for the low-voltage consumers and the 40-liter (10.6 US gal) fuel tank are located over the rear axle. The luggage compartment remains spacious. In the standard configuration, it has a capacity of 280 liters (9.9 cu ft) and 1,120 liters (39.6 cu ft) with the rear seat backrest folded down.
With a volume of just eight liters (0.3 cu ft) and weighing just ten kilograms (22.0 lb), the power electronics in the engine compartment, which include a DC/DC converter for connecting to the 12-volt electrical system, are compact and lightweight. Six high-performance transistors convert the direct current supplied by the battery into three-phase current for the electric motor.
When charging the A3 Sportback e-tron, the charger converts the incoming alternating current into direct current for the battery. The charging port is located in the Singleframe grille behind the four rings, which fold out to the side. Besides a status light, there are also two buttons here. The driver uses them to either start the charging process immediately or via a timer for the next trip. Timer charging can also be programmed via a special menu in the MMI navigation plus or the new Audi connect e-tron services.
The Audi A3 Sportback e-tron comes standard with a charging system comprising a control unit with graphical display, and a portable charging unit for the car with two power cables with the 120V and 240V plugs. For use at home, the e-tron charging cable can be mounted in a wall box (standard with the e-tron plus package)—snap the unit into place, and have access to Level 2 charging. The charging dock can be locked to protect the equipment against theft, and a PIN code provides additional security.
240-volt charging replenishes the battery in about 2 hours and 15 minutes; recharging through a 120-volt outlet takes approximately 8 hours. Home installation of a 240-volt outlet and home charging station are optional.
The available A3 e-tron smartphone app allows drivers remotely to check on the status of their A3 e-trons. It can be used to check battery status and for “charge planning”—setting times for charging to automatically begin. The driver can also use the app to adjust climate control remotely for added comfort and energy savings.
Audi energy offering. To ensure driving an A3 Sportback e-tron is convenient and sustainable, Audi is providing the Audi energy portfolio of products with each vehicle sold. Audi energy includes:
The standard Audi-designed mobile charging system that works with standard US household outlets or 240-volt service;
The option for professional 240-volt plug installation through Bosch Automotive Service Solutions, which can lower home charging times to around 2.25 hours;
Optional solar power installation with rebates through SunPower; and
Audi contributions to environmental conservation programs through 3Degrees to help offset the carbon footprint of every A3 Sportback e-tron sold.
Drive modes. The A3 Sportback e-tron offers four drive modes:
- EV mode, in which the vehicle is powered only by the electric motor for a smooth and quiet ride featuring quick acceleration. This is the default start-up mode, regardless of which mode might have been operational at the time of the last shut-down.
Hybrid mode conventionally allows the car to select the most efficient power source—either EV, Hybrid or gasoline.
Hold Battery mode allows hybrid driving while preserving EV range for later use.
Charge Battery mode uses the gasoline engine to recharge the battery while driving at highway speed. The electric engine can also supplement the gas engine to provide an extra boost of power when desired.
In driving the A3 in a combination of high-speed Interstate cruising; very low-speed bumper-to-bumper Interstate crawling; and stop-and-go congested in-city driving, we tended to default to EV mode in the city, and to also use EV mode on the Interstate, until the state of charge began shrinking toward the bottom of the dial of the powermeter charge indicator. At that point, a quick switch to Charge Battery mode worked quite well to raise the SOC back to the point where it was good-to-go for the next city segment, while preserving the performance sometimes required on the highway.
|Screen shot from the MMI showing some of the available e-tron statistics: 58% of this segment of the drive was completed in electric mode. Click to enlarge.|
The driver can also use Audi drive select to configure the character of the car according to the modes comfort, auto, dynamic and individual. The system, which comes standard, also controls the optional components adaptive cruise control and adaptive light.
Connected and safety technologies. The A3 Sportback e-tron features technology both specific to its being an e-tron as well as general Audi features.
The MMI operating system has an electronically extending screen, its terminal housed in the console of the center dashboard. An available touch pad is incorporated into the rotary MMI control wheel, which offers intuitive and simple operation. The touchpad supports character recognition for some applications—such as entering your PIN to sign into Audi connect, for example. Much easier quickly to trace the number on the pad rather than select it.
The available MMI navigation plus system features 4G LTE based technology, MMI touch, and two SD card slots for MP3 files.
An NVIDIA graphics processing unit (GPU) generates the complex three-dimensional images used in all online, voice control, media navigation and telephone functions.
Audi connect is the label for online services for the A3 Sportback e-tron that allow drivers to control and regulate numerous functions. Audi has developed an app for this purpose with informative graphics that runs on modern iOS and Android smartphones. Audi also offers a special web portal for, among other things, the registration and activation of the services (www.a3etron.audi.com).
The Audi connect e-tron services enable drivers remotely to check the status of car—e.g., battery charge and electric range—and also call up a variety of service information and the car’s location. Drivers can also manage charge planning remotely. They have the option of starting and stopping charging or setting the timer to reflect when they next plan to drive the car. They specify in detail at what time on what days they want to drive off with the battery fully charged.
The climate control planning function is used to activate the air conditioning or the optional auxiliary heater on an ad hoc basis or according to a timer schedule. In the latter case, which is referred to as preclimatizing, the car draws the energy required from the outlet so as not to compromise the electric range.
Owners can view a variety of driving data, such as average electricity consumption or average speed, on the web portal or on the mobile app.
MMI navigation plus uses 4G LTE to deliver the tailored services of Audi connect to the driver—from navigation with Google Earth and Google Street View.
Driver Assistance. The Audi A3 Sportback e-tron offers several advanced technology features, including:
Standard Audi pre sense basic system which helps detect when an emergency maneuver is being made and prepares the vehicle and its occupant restraint systems in advance of a possible collision.
Available Audi side assist, including lane change assistant, operating at speeds above 19 mph and providing visual warnings located in exterior mirror housings.
Standard electronic cruise control with coast, resume and accelerate features.
Available Audi adaptive cruise control with stop & go.
Available Audi active lane assist: when the system detects that the driver is leaving the lane without signaling, the car, through gentle corrective steering efforts, will assist the driver to remain in the lane.
Audi pre sense front: includes brake assist or partial braking when the risk of a collision is detected.
Subjective impressions. The A3 Sportback e-tron is an extremely attractive entry into the burgeoning plug-in hybrid market in the US. The A3 e-tron is very comfortable and fun to drive, especially given its power, handling and smoothness. Its cargo space and split fold-down rear seats enhance its general utility.
It’s a great EV when it’s in electric mode, and a terrific hybrid when in that mode. The engine, one of the smaller displacement engines currently used in PHEVs, never sounds as if it is straining to deliver, even on kickdown for some aggressive passing in hybrid mode, for example.
Audi’s MMI system continues to develop and mature as the developers refine the core functionality as well as the various human-machine interfaces.
Even the pricing seems somewhat in line. US prices for the 2016 A3 Sportback e-tron will begin at $37,900 for a Premium package, rising to $46,800 for the top-end Prestige package. Purchasing customers may qualify for applicable state and federal incentives and tax credits (e.g., federal tax credit of $4,168). In California, for example, this will likely net out to $33,157 for the entry model, Brabec noted in his presentation.
As a comparison, for the 2016 A3 family, the entry point is the $29,900 A3 1.8T, which jumps up to $35,600 as a Cabriolet. The A3 2.0T starts at $32,900, with $38,600 for the Cabriolet version. The sidelined A3 TDI started at $33,200, while the top-end S3 enters the market at $41,400.
The A3 e-tron trounces all of those models in terms of fuel economy and emissions, and performs as well as or better than half of them.
The quibble that some may have with the entry may be the decision on the size of the pack and the resulting amount of all-electric range. Driving in EV mode in the A3 e-tron is great—so great, in fact, that it’s a bit disappointing when you’re on the highway cruising along, and realize that you need to jump over to hybrid mode because the battery is depleted. (Or, if you’re not paying that close attention, the system will switch over for you.)
However, with a few notable exceptions—high (Volt) and low (Prius PHV)—that mid-range pack is where many of the new plug-in hybrid entries are focused, likely due to a combination of trying to keep the cost down and the weight manageable. While not an ideal solution, the Charge Battery mode option is a practical workaround that extends EV range without the benefit of a plug.
This initial electrified entry from Audi in the US is a strong one; the obvious care that has gone into the software for the systems and the motor also makes us quite eager to see what the next Audi electrified offering, either PHEV or pure EV, will bring.