e-tron, Audi's first-ever fully electric vehicle, goes on sale in the U.S. in the second quarter of 2019. (Audi)

Audi unveils production version of first-ever EV: e-tron

It seems safe to say the global shift to battery-electric vehicles now is in full swing, with the Volkswagen Group’s Audi brand unveiling on September 17 its first electric vehicle (EV), the e-tron, barely a week after chief rival Mercedes-Benz revealed its EQC and mere months after Jaguar launched its i-Pace. An additional sign of the times: all three new luxury EVs are crossovers.

In a glitzy global reveal event in San Francisco, Audi finally pulled the sheet off the production version of the e-tron, some three years after it was first shown as a concept. Production already is underway in Brussels, Belgium, with Audi intent on delivering the first customer vehicle in Europe by the end of 2018. The company is cautiously pegging the start of U.S. sales for the second quarter of 2019 and the e-tron will not be inexpensive, with the heavily-equipped Prestige “base” model starting at $74,800 and moving to $86,700 for First Edition (limited to a run of 999 units), which tops the three-trim e-tron lineup.

Bodystyle jackpot
Although Tesla is the obvious target for any new luxury-brand EV, Audi’s advantage (as well as for the Mercedes-Benz EQC and Jaguar i-Pace) is that the e-tron is a crossover, while Tesla remains oriented towards sedan body styles. It’s a critical point for U.S. consumers, said Audi of America’s Matt Mostafaei: “The e-tron is a midsize SUV first and an electric car second.”

Derived from the VW Group’s essentially powertrain-agnostic MLB (front longitudinal-engine) platform, the 5-seat e-tron is sized conveniently between Audi’s midsize Q5 and the fullsize, 3-row Q8 crossovers: the e-tron is 193 in (4902 mm) long and 86.3 in (2192 mm) wide, with a wheelbase of 115.1 in (2924 mm), making it 4 in (102 mm) longer in wheelbase and nearly 10 in (254 mm) longer in overall length than the Q5.

Seen at its San Francisco revealing, the e-tron has an ample footprint—and weight to match. Although the company’s press material did not reveal a curb weight for the crossover in either European or U.S. configuration, one Audi source pegged the e-tron at a stupendous 2490 kg (5490 lb)—not an unimaginable figure considering the battery pack alone weighs a claimed 700 kg (1543 lb).

Big battery, big charging ability
The 95 kWh lithium-ion battery pack is comprised of 432 pouch-type cells grouped in 36 modules; the cells are made by Korea’s LG Chem. Audi designed and builds the clever battery enclosure, incorporating exceptional protection from crash intrusion via a robust, largely-aluminum structure that also was specially conceived to facilitate thermal management with incorporated cooling circuits throughout the battery pack.

The e-tron’s four coolant circuits are “one of the most complex systems of the car,” Jens van Eikels project leader of e-tron car line, told Automotive Engineering. In addition to closely managing the temperature of the battery pack, coolant also flows to a drive motor at each axle, as well as to the heat pump that provides cabin climate control. The heat pump is some 15% more efficient than a conventional HVAC system, van Eikels said, while the special coolant “spears” designed into the drive motors are so effective in drawing heat from the motors and integrated single-speed planetary transmission that there is no need to cool the transmission oil, also eliminating the need for an oil pump.
Another cooling innovation: the coolant lines do not directly contact the battery modules, instead running in a grid-like pattern in the structure itself; heat transfer is accomplished via a special gel that surrounds the modules.

Audi makes much of the built-in charging capability of the e-tron and the thermal-management performance also plays a role in the speed and capacity at which charging can take place. Onboard for U.S. models is a 9.6-kW charger that Audi said is the highest capacity of any currently-available EV. It means a household 240-volt/40-amp circuit can provide an 80% recharge of the 95-kWh battery pack in about 8.5 hours.

The e-tron can be charged at up to 150kW, however, through its standard SAE J1772-spec Combined Charging System (CCS) connector. At the 150-kW rate, the battery pack can be recharged from 80% depletion in less than 30 m. At the 50-kW rate currently available at some public charging stations, an 80% recharge will require about 80 m.

Those without the requisite household 240V circuit surely will want to install one, however, as charging on standard 120V current would require some 90 hours! To that end, Audi has entered an agreement with Amazon Home Services to broker installation of a 240V circuit. Audi sees the charging end game, however, at a 350-kW rate—now starting to be installed by the VW Group’s Electrify America subsidiary—that would recharge the e-tron in less than 12 m.

But perhaps the most-important aspect of battery performance remains unaddressed for now: Audi said it does not have official driving-range figures for the e-tron. The best-available figure at the time of the e-tron’s global unveiling was the 400-km (249-mile) rating from Europe’s new Worldwide Light-vehicle Test Procedure (WLTP), which may be reasonably close to what U.S. regulators will derive.

New twist: electric quattro
Standard for every e-tron is an AC asynchronous traction motor at each axle that imparts all-wheel-drive capability with a new level of precision, said Dr. Joachim Dorr, a powertrain engineer for the e-tron, who called the electric-drive quattro system “the next chapter in Audi all-wheel-drive technology.

“In my personal opinion,” he added, “the e-tron has the best quattro drive we’ve ever made.”

Although Audi said U.S.-specification output figures are yet to be finalized, information at the crossover’s press reveal indicated the asynchronous motor at the rear axle (which under normal driving is designed to deliver the majority of tractive torque) is rated at approximately 140 kW (188 hp). The front-axle motor generates approximately 125 kW (168 hp) and the combined torque output is a maximum of 413 lb·ft (561 N·m).

A special “boost” mode—engaged by pinning the accelerator pedal whenever the drive control is in “sport” mode—will command a maximum of about 300 kW (402 hp) and 490 lb·ft (664 N·m). Using this function delivers the e-tron’s best 0-60 mph (0-97 km/h) acceleration time of 5.5 s, Audi said. Early critics noted the acceleration performance is not particularly impressive and likely is related to the e-tron’s not-inconsiderable weight. The e-tron also seems targeted at the middle of the luxury utility-vehicle market, where extreme performance is not a high priority; Audi might be expected to in the future offer performance variants of the e-tron.

Project leader van Eikels said the all-electronic quattro “tuning” is particularly fast-acting and also allows for a certain degree of torque vectoring at the rear axle and accompanies braking at individual wheels to impart a torque-vectoring effect in less-strenuous driving situations.

The drive motors are built by Audi at its longstanding IC engine plant in Gyor, Hungary. The rotors use no rare-earth elements and the stators are Audi-designed and built, with other motor components coming from external suppliers Audi did not detail. By the end of the year, the company intends to make about 400 motors daily under a new modular production system that sees each motor travel to assembly stations on automated carts rather than an installed conveyor line.

The e-tron’s drive system of course incorporates driver-selectable degrees of regenerative braking effect. Audi of America president Scott Keogh called the system “the most-efficient battery recuperation to date,” adding that it can contribute up to 30% of the e-tron’s total driving range.

Start of the wave
The e-tron is the beginning of Audi’s push to electrification, Keogh said. By 2025, Audi intends to have 12 EVs in its global product portfolio and sees one-third of sales comprised of electrified models.

Following the e-tron is a “Sportback” version next year, while a sport-oriented GT concept coupe is slated to be revealed at the Los Angeles auto show in November.
  Continue reading »