It takes three to five years for a car company to take a new model off the drawing board and bring into showrooms. That kind of lead time means on the day it's launched, even the most advanced vehicle is at least three years behind what is truly considered to be cutting edge. Concepts and show cars are a different story. They are usually developed in under two years, and in extreme cases like the Audi e-tron Spyder, they can be developed and built in as little as five months.
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Over the last decade, the primary focus of automotive advancement has been on alternative powertrains. Since diesel and hybrid systems have proven viable and efficient alternatives to strictly gasoline power, it would seem like a natural combination to use the two together for one extra-efficient, planet-saving drivetrain, but there have been precious few attempts at combining the two, and so far none in the sports car world. Why has it taken so long to put the peanut butter and the chocolate together? Simple answer: cost and weight. Both diesel and hybrid drive trains carry a weight penalty; hybrids more than diesel. Both are considerably more expensive to produce than a typical gasoline engine, so getting the two together takes an exact set of circumstances that doesn't come along very often.
This particular e-tron works because one, it is a one off-concept where price is no object, and two, the entire car was essentially designed around the drivetrain from the beginning, so several concessions were made in advance. Overly heavy and superfluous accessories like a glove box, air conditioning, and a roof were left behind in the garage. Batteries, a fuel tank, a 300-horsepower twin turbo direct injection diesel V-6, computers, and two 44-horsepower electric motors take up all the space that might normally be used for groceries. Even with all the weight savings and lack of amenities, the e-tron still weighs in at just under 3200 pounds -- just 300 pounds lighter than an R8 with a 4.2-liter V-8 and a roof.
Audi will tell you the e-tron is based around R8 architecture, but in reality, the only part of the chassis sourced from the production supercar is the floor pan. Even the center tunnel was modified, since it no longer houses a drive shaft. The rest of the space frame is hand-built, wrapped and stretched around the drivetrain. At present, Audi is not allowing photography of the naked e-tron, but they did allow us to take a look after the cameras were put away. Under the very modern yet still familiar carbon-fiber body, the one-off is pure race car. Made almost entirely of aluminum square stock, extrusions, die-cast lugs, and stress skin sheets, the e-tron is a thing of beauty that will inspire poetry from bridge builders and birdcage aficionados.
The suspension is also a one-off design utilizing an SLA system in front with a multi-link setup in back made of forged aluminum arms. As it is a prototype, variable rate coilover dampers were used instead of an magnetorheological system that would certainly be used in a production vehicle. The suspension is stiff but not punishing, at least on the mostly smooth canyon roads we used for the drive. Suspension travel seemed to be somewhat limited, but didn't have a negative impact on handling during our somewhat constrained driving.
<blockquote align="Center"><p>The hybrid system provides energy recovery, the ability to use all-wheel drive on demand, and can be used for continuously variable torque vectoring of the front axle
The e-tron has a nearly 50:50 weight distribution with almost all the weight located between the two axles. These factors alone would add up to a superior handling vehicle. However, Audi has yet another trick up its sleeve. Not only does the hybrid system provide energy recovery and the ability to use all-wheel drive on demand, using two separate motors, one for each front wheel, means it can be used for continuously variable torque vectoring of the front axle. Being able to push the power around from side to side has allowed car builders to achieve new feats of handling. Audi claims that with an electronic torque vectoring system, the owner could essentially program the car to behave however they desire. While we do believe Audi could accomplish this, we don't believe lawyers would ever allow Joe Public to go from normal to drift-king mode with the push of a button.
During our drive, the e-tron was set-up to be pretty safe and easy to drive. In most situations, the front drive was nearly imperceptible. There was no torque steer, and rolling in and out of the throttle didn't change feel or effort. Around the tighter corners in the canyon, the e-tron understeered slightly and was exceptionally normal for a one-off exotic. Once we got comfortable and stopped dwelling on the idea of doing something irreversible to a car that's irreplaceable, our speed picked up. Charging into an uphill left-hander, the car started to push just slightly, with more scientific curiosity than common sense. The throttle was pinned, and the unmuffled diesel boomed and clattered. Instead of breaking the rear tires loose into oversteer, or picking up the front end and making matters worse, the two electric motors joined in and pulled the front end around, killing the understeer and throwing the car out of the corner.
It is at the limits when enthusiasts will really start to appreciate the value of hybrid drive. Sure, it might be good for the environment, as Audi is claiming something like 107 mpg for the plug-in hybrid. I don't know exactly how they got to that number, and I'm not sure I care. What I care about is being able to tune a car's handling with torque vectoring, and as much as I love watching brake rotors glow, I don't want to think about how much energy is being thrown off illuminating the inside of a wheel. If the car can recapture that energy, store it, and use it later, I'm all for that.
