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4T : Reviews & Road Tests

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19 November 2010


When Audi dropped the otherworldly looking e-tron concept car on the public at the Frankfurt Auto Show back in the fall of 2009, illustrious board member and development boss Michael Dick promised that journalists would be behind the wheel of a running example in about a year. He went on to say that series production would follow by 2011. And though Audi has shown itself as credible when it comes to transforming cars from concept to reality, the claim still seemed a bit far-fetched.

Now, here we are, 14 months after the e-tron concept’s launch and an Audi engineer ushers this journalist through an entranceway to an awaiting matte grey R8. The driver’s door is ajar and I can see the familiar R8 cabin inside, albeit slightly modified with a Recaro racing seat. The gearshift lever has been swapped for one of the shift-by-wire leather grab handles from the latest A8 and it’s been paired with an alloy base that fits the R8’s center console.Driven: 2011 Audi R8 e-tron PrototypeAs I climb into the Recaro, I note even more changes. To the left, replacing the tach, is a green-trimmed “efficiency” gauge that numbers from 20 to 100 and is separated into zones labeled “efficiency”, “max” and “boost”.

Between the two main analog gauges, the second being the usual speedometer, is a made-to-fit full color display quite similar to what’s in the new 2011 A8. This display alone would be enough to make any R8 owner green with envy, but the truly green theme here is just what the readout monitors.Driven: 2011 Audi R8 e-tron PrototypeAs is typical of many of the latest Audis, there’s an upper side cutaway image of the car depicted on the screen. Above it is a charge indicator and the diagram is dynamic, able to depict drive or braking forces via animated green “tire tracks”. Yes, this R8 is electric and Michael Dick is about to come through on that promise. Well, at least half of it.

Granted, this isn’t the first time I’ve seen this car. As part of an exhibition of alternative fuel and primarily electric cars, Audi ran this R8 publicly for the first time last June at Le Mans. At that time Frank Biela piloted the car around the Circuit de La Sarthe, which explains the presence of the Recaro racing bucket.Driven: 2011 Audi R8 e-tron PrototypeFrom the outside, there’s little to differentiate this R8 e-tron prototype from any other run-of-the-mill R8. Peel the neon green “e-tron” decals off the side of the car and buff off the matching ring accents on the set of alloys pilfered from the parts bin of the V10 model and this relatively understated coupe could slip down any street as unassumingly as any R8 might have a right to do. The only other outwardly visible changes between this R8 e-tron and its petrol-burning production brethren is a lack of exhaust pipes, a carbon fiber rear valance that juts out a little further than normal and functional carbon fiber vent louvers in place of glass on the rear decklid.

Not that there’s any sexy aluminum runners to show off under that lid, anyway. Power on tap for this R8 comes from four asynchronous electric motors that provide torque to each individual wheel, adding a whole new facet to Audi’s quattro crown jewel. Add it all up and the R8 e-tron boasts a total of 313 hp, which may not sound like a lot but is well offset by a claimed 3319 lb-ft of torque at the wheels, all available from a dead stop.Driven: 2011 Audi R8 e-tron PrototypeIf those numbers confuse you, you’re not alone. I had a hard time wrapping my head around them as well and wasn’t sure what to expect as I steered the R8 e-tron out of its garage and onto a predetermined road course laid out across the extended parking area of the Audi Sportpark stadium on the outskirts of Ingolstadt.

At first I went easy on the throttle and staged the car for an initial straight. Would it feel less than an R8 given it is down more than a quarter on horsepower compared to the V8? Or, with 3319 lb-ft of torque immediately available, would it rip up the pavement, lobbing chunks of tarmac through the glass front doors of the stadium and onto the turf of the soccer field inside?

In reality, the R8 e-tron did neither. A wall of torque comes on right away, quick like the R8 V12 TDI design study we drove back in 2008. It’s no earth-shattering wall but it does come on quite abruptly. As speed builds, the pace feels somewhere above that of a TT RS but also south of an R8 4.2. The only sound is a slight whir of the machinery and a slightly growling undertone that actually seems to be coming from the tires. (Watch the video footage below in order to see and hear for yourself).

Audi says sound could be part of the plan in its electric e-tron model design but this R8 e-tron prototype emits nothing but the sound of its actual drivetrain and undertone from the tires. While future e-trons may emit hints of the futuristic Audi RSQ that starred in alongside Will Smith in the movie iRobot, this e-tron was a mixture of raw electromechanical operation and rubber on the road. What noise existed was kind of cool and otherworldly, but overall volume was quite low.Driven: 2011 Audi R8 e-tron PrototypeAt the end of the straight I push the car harder into the turn. There’s not a whole lot of room to build up pace and the cost on this one-off prototype is off the charts. I remember Audi e-performance boss Frank van Meel mentioning to me that the car does not yet have any ESP systems either so there’s little intent on my part to perform an experiment in e-hoonage.

The car does feel well-balanced. Its liquid-cooled lithium ion battery and all associated electronics are mounted just aft the passenger compartment. The setup gives the R8 e-tron a 42:58 weight distribution, identical to the R8 V10.

Harder into a turn, the R8 is also more than willing to hold its line. Audi has fine-tuned the power delivery of the motors to mimic a production R8s when it comes proportion, sending 70 percent of the power to the rear in normal conditions. If slip occurs, power delivery can change back and forth in fraction of a second. And, like the Sport Differential equipped in the new S4, the system can also make use of simulated torque vectoring to further hold the cornering line.

There’s a second straight on Audi’s test course so we hammer the throttle again. Audi claims the car is capable of 0-62 mph sprints in 4.8 seconds. We didn’t have any testing equipment to verify this number, but if that is true then the R8 e-tron matches the pace of the R8 4.2. Without the sound and emotion of a screaming motor, though, it does feel slightly slower.Driven: 2011 Audi R8 e-tron PrototypeHot into a 180-degree turn back toward the stadium we stand on the e-tron’s brakes. This R8 is fitted with a combination electric and hydraulic setup that can convert some of the kinetic energy we’re scrubbing off back into electricity, feeding it back to the car’s battery. Like the system used in the Audi A1 e-tron, the recovery system is staged and can be adjusted via controls on the steering wheel. Beyond that the hydraulic element comes into play for the heavy duty braking that we’re already quite used to in any normal R8.

Maneuvering the R8 e-tron through the turnaround, we make a point of focusing on steering feel. The car makes use of forged aluminum double triangular control arms similar to motorsport designs at the front and also has an electro-mechanically assisted steering rack with direct gear ratio. Response is direct, while weight is heavier and a little more artificial than a production R8.

Sitting on the tarmac, this R8 e-tron prototype weighs in at a respectably low 3527 lb. That is just a bit under the weight of today’s R8 4.2, despite 1212 pounds coming from the battery alone.

Why such a heavy battery pack? Unlike the Audi Q5 Hybrid and A1 e-tron we also tested while in town, the R8 e-tron relies solely upon battery power and has no range-extending backup. Because of this, a higher capacity unit was necessary, capable of storing 53 kWh. Audi says that much power in reserve is capable of bestowing upon the R8 e-tron a range of about 155 miles.Driven: 2011 Audi R8 e-tron PrototypeShould one plug the R8 e-tron into household power, the recharge of a fully discharged battery will take up to eight hours. A high voltage recharging station would shave that time down to about 2.5 hours.

Audi says it is on track to begin series production of an R8 e-tron by late 2012. At that time cars very similar to what you see here will roll out of the company’s Neckarsulm assembly facility and into the awaiting arms of customers. This may be a year longer than Audi first stated in Frankfurt but we suspect that buyers will find the car well worth the extra 12 months’ wait.

Check out video and a full photo gallery of the R8 e-tron via the links below.

Video Footage

Additional Photos

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