2015 Acura TLX Makes Competition Debut at Mid-Ohio

The 2015 Acura TLX sports sedan made its debut earlier this year at the North American International Auto Show (NAIAS) that Chris and I attended. Weirdly, despite tweeting about it frantically and taking a few pictures of the car’s advanced engine, we didn’t write an article about it then. Consider the car you see here, then – the 2015 Acura TLX GT race car – a lesson in taking Acura seriously.

Set to debut at this weekend’s Mid-Ohio World Challenge GT race, a support race for the IndyCar “main event”, the 2015 Acura TLX GT will compete in the top category of the Pirelli World Challenge, facing competition from the like of the Audi R8, Bentley Continental Supersport, Dodge/SRT Viper, Ferrari 458 Italia, McLaren’s MP4/12C GT, and the Porsche 911 GT3 RSR.

Serious machinery, in other words.

RealTime Racing owner/driver Peter Cunningham will be behind the wheel of the new Acura, and hopes the flexible engine and willing chassis will help him overcome his more powerful competitors. “The Pirelli World Challenge has a lot of strong competitors in GT, but the TLX is the only all-wheel-drive car in the category. For our four-door sedan to be racing head-to-head with the likes of Ferrari and Lamborghini … is pretty cool,” he said.

Developed from the production Acura TLX by HPD and RealTime Racing, the Acura TLX GT features an HPD-modified chassis, Honda’s Super-Handling (SH) all-wheel drive system, and aerodynamic performance parts approved for Pirelli World Challenge competition, and is powered by a direct-injected, twin-turbocharged V6 engine similar to the one used by Honda in the IMSA DP category.

“We’re excited to debut the Acura TLX GT race car in front of our ‘hometown’ audience of associates from the many Honda facilities in central Ohio,” said Art St. Cyr, President of Honda Performance Development and Vice President of Auto Operations for American Honda. “The competition in the Pirelli World Challenge is fierce … (but) Acura has never shied away from a challenge. Instead, we seek it out, both on-track and in the marketplace.”

Big words from everyone. Here’s hoping the Honda guys and the RealTime Racing 2015 Acura TLX GT can deliver!

Source | Photos: Honda.

Audi A8 E-Tron Will Use TDI Engine

 

A report in Auto Express says that the upcoming Audi A8 e-tron will use it’s all new 3.0 liter TDI engine to power the plug-in hybrid.This may give Audi an efficiency edge on its PHEV competitors, cars like the Mercedes S Class HYBRID and the BMW ActiveHybrid 7 Series plug-in, both of which will employ a gasoline engine instead. The Audi TDI package should beat the 100 grams of CO2 per kilometer target so important to European buyers, and deliver a ton of torque as well.  Dr. Ulrich Hackenberg, Audi’s head of technical development, said that:

The 3.0-litre e-Tron will be used in different cars. The plug-in hybrid is an exciting combination.

The V6 TDI system will likely find its way into the rest of Audi’s larger automobiles like the Q7 and A6 as the company continues its push to offer a PHEV version of every model it sells. Well, almost. The Audi R8 e-tron won’t be offered as a hybrid, but will instead offer an all electric option on special order only. Audi will use a 1.4 liter gasoline engine hybrid in its smaller cars like the A3 e-tron, scheduled for sale in 2015.

The TDI hybrid will be good for 368 hp and 515 lb-ft of torque, and will have an electric-only range of 30 miles or more, joining its smaller sibling, the Audi A6 e-tron, which will go on sale in China first. Fuel economy figures weren’t discussed, but with more than 500 ft-lbs of torque on tap, I’d be happy with anything over 25 MPG.

Source: Gas2

New 3.0 Liter Audi V6 TDI Good for 40 MPG, 442 ft-lbs of Torque

Starting next year, the new Audi 3.0 liter V6 TDI engine will be offered across its lineup, offering more power and efficiency over the outgoing model. You’re gonna like these numbers; in addition to being 13% more efficient, the new Audi motor can make up to 442 ft-lbs of torque. Got any tree stumps you need yanked out of the ground?

While that may not be the best use of your luxury sedan or SUV, with that kind of torque you could certainly make a go at it. The new V6 motor features 90-degree cylinder banks and efficiency-improving features like low-friction piston rings, a variable-load oil pump, and an improved heat management system that ensures the engine runs at peak efficiency. Audi will offer the V6 in two different flavors, making either 215 or 268 horsepower, versus the 240 horsepower of the outgoing model.

Audi hasn’t specified what cars will get the new V6 TDI, but in the current Audi A6 TDI, the 3.0 liter engine is good for 38 MPG on the highway and 24 in the city, for a combined rating of 29 MPG. A 13% boost should easily push the highway mileage over 40 MPG, making the A6 TDI one of the most efficient large sedans you can buy. The new engine even meets the super-strict Euro 6 emissions standards, averaging 15 grams of CO2 less than its predecessor. Other likely candidates for this engine besides the A6 are the Audi A8, Q5, and Q7.

I mean really, what’s not to love here? 40 MPG. Almost 450-ft-lbs of torque. I’m lovin’ it anyway you put it.

Source: Audi

Audi to introduce four new TDI® clean diesel models to the U.S. Market at the L.A. Auto Show

PRESS RELEASE

The Audi A8 TDI clean diesel achieves manufacturer estimated fuel efficiency of 24 city/ 36 highway

New 3.0 liter V6 TDI clean diesel models will include the Audi A8, A7, A6, Q5 and an updated Q7 TDI

Audi to use #FuelForThought at the LA Auto Show to create a social media experience at the display and online

Audi of America announces the arrival of the new TDI® clean diesel models for the Audi A8, A7, A6 and Q5 to debut at the Los Angeles Auto Show. The addition of these four models marks the first time Audi will feature a full lineup of TDI clean diesel vehicles in the U.S. as they join the updated Q7 model. Each TDI vehicle delivers up to 30% better fuel economy and 30% lower carbon dioxide emissions than gasoline engines*, resulting in longer range and fewer trips to the fuel pump. By having more density than gasoline, diesel packs more energy content in the same amount of fuel, which helps maximize the miles per gallon when that energy is released during a more powerful combustion cycle.

The TDI clean diesel engine lineup adds to Audi's list of advanced technologies that help enhance fuel efficiency, including Audi ultra® lightweight technology, such as the use of aluminum, and the AFS® frame technology.

"Owners of Audi TDI engines have helped save over 4 million gallons of gasoline, or the equivalent of more than 240,000 barrels of foreign oil, since the introduction of Audi TDI to the U.S. in 2009**," said Scott Keogh, President, Audi of America. " And, TDI technology delivers better fuel efficiency without sacrificing performance."

In order to fuel the conversation surrounding the benefits of TDI technology in the U.S., Audi will use the hashtag, #FuelForThought and invite fans to join the conversation through a social experience at the display and online.

Audi A8 TDI
The flagship of the Audi brand, the A8 TDI, makes a powerful statement in achieving a manufacturer estimated fuel efficiency of 24 MPG in the city and 36 MPG on the highway*. The A8 TDI clean diesel executive sedan embodies superior design and progressive advancements which sets new standards for luxury sedans in terms of uncompromising efficiency and performance. The new 2014 A8 sedans dramatically expand the flagship's engine offerings by moving from two variants (4.2 liter V8 and W12) to six, including: the entry level A8 3.0T V6; the 420 horsepower A8 4.0T V8; the new Audi S8 4.0T V8; the A8 6.0 liter W12; and the new A8 3.0 TDI V6. The new 3.0 liter TDI clean diesel engine generates an astonishing 240 horsepower with 406 lb.-ft. of torque and seamlessly goes 0-60 in 6.4 seconds.

Audi A7 TDI
The Audi A7 TDI clean diesel is the pinnacle of design and is now more fuel efficient than ever. Without compromising design or performance, every detail of the A7 TDI delivers a striking visual statement. The A7 was the first car in the world to feature available factory-installed Wi-Fi (for up to 8 passenger devices) with Audi connect™ and MMI® navigation plus with 3D Google Earth™ maps. From the groundbreaking available MMI touchpad and its gracefully integrated display screen, to the state-of-the-art head up display, the Audi A7 TDI is the perfect marriage of progressive design, efficiency and versatile space.

Audi A6 TDI
One of Audi's most innovative and technologically advanced models to date, the A6 TDI performance sedan sacrifices virtually nothing in performance, comfort or design. As with the successful A6 TFSI® gas engines, the A6 TDI clean diesel engine can make up to 2,000 decisions per second. Available driver assistance systems include night vision assistant, head-up display and Audi pre sense plus that helps detect imminent collisions and initiates protective measures when needed. Other available intelligent features include head-up display and a MMI Touch pad that recognizes handwriting, along with available Audi connect – the first factory-installed wireless internet connection that enables Google Earth maps, Google Local Search, and a WiFi hotspot for up to eight passenger devices.


Audi Q5 TDI
The Audi Q5 has proven itself an absolute success as one of the best-selling models in the Audi lineup. For the 2014 model year, the Q5 will receive the new TDI engine which will allow for better fuel economy along with increased torque. The Audi Q5 TDI combines the driving appeal of a sedan with high versatility of its interior space and many practical solutions for recreation and everyday driving. Audi has further sharpened the profile of its performance SUV in its design, technological advancements, driver assistance systems and fuel efficiencies. The new TDI clean diesel engine marks the fourth engine variant for the Audi Q5 model lineup, adding to the current four-cylinder 2.0T, the 3.0T V6, and the Q5 hybrid.

Audi Q7 TDI
The Audi Q7 continues to establish the standard in progressive design, sophisticated technology and fuel efficiency in premium sport utility vehicles. The benefits of TDI clean diesel technology are further enhanced through the revised V6 TDI engine that offers a 10 percent efficiency improvement compared to gasoline engines. The revised TDI clean diesel engine has an increased output of 240 horsepower and 406 lb-ft of torque that helps improve performance and offers impressive fuel economy with an EPA estimated 19 city/ 28 highway miles per gallon*. The incredibly efficient TDI clean diesel engine enables the Q7 TDI to achieve a range in excess of 700 miles per tank***.

2014 MY Availability
A8 TDI Spring 2013
A7 TDI Fall 2013
A6 TDI Fall 2013
Q5 TDI Fall 2013

Pricing for all 2014 MY vehicles to be announced at a later date

2013 MY Availability Starting MSRP
Q7 TDI Since September 2012 $52,000

* EPA estimates. Mileage will vary.
** Based on total A3 TDI and Q7 TDI vehicles sold, average nationwide gasoline fuel prices, and EPA estimated annual average miles driven.
*** Range based on 28-mpg highway EPA estimates and a 26.4-gallon fuel-tank. Mileage will vary.

Where stated, fuel economy values (mpg) are EPA estimates. All other fuel economy values are forecast manufacturer values for the USA; those EPA estimates were not available at time of release. Audi Connect and SiriusXM Traffic services may require additional subscriptions. MSRPs exclude taxes, title, transportation, options and dealer charges.

2012 Audi A8 Hybrid

When it comes to the hybrid market, we assume – as most of you probably do as well – that the United States is at the top of the list to get whatever hybrid models an automaker builds. That vision is apparently altering for the Germans, though, as Audi is not bringing this A8 Hybrid to the States, instead favoring Western Europe and particularly Asia.

The start of deliveries in Europe already commenced in May, and Asian deliveries will start by 2013 as Audi mulls bringing the long-wheelbase version there, as well as a right-hand-drive model. The choice to not invite North American consumers to the party might not be a forever sort of thing, but at least for the next few years, the plan appears to be set in stone.

To be honest, Audi's full parallel hybrid strategy, along with that of parent Volkswagen Group's larger cars and SUVs in general, isn't terribly amazing – there's no thinking going on outside of the box here. Across the entire VW corporate family, the better choice for these bigger cruisers is always the range of outstanding diesels that generally weigh less and can cost less than their hybrid brethren. Nonetheless, Audi's high-tech image demands that the brand show it can play in every alternative propulsion sector. With China being Audi's best market by far, this A8 Hybrid has that nation writ all over its business plan.

What is, however, a nice upgrade to Audi's hybrid efficiency message is that the engine in this gas-electric A8 is the widely praised 208-horsepower 2.0-liter TFSI four-cylinder, not just a modified V6 or V8 that would lower development costs but hike the price beyond credibility. This four-cylinder choice helps contain both the weight and the price of the project. In Germany, the A8 Hybrid sells for €70,700 after all initial taxes. A more generously equipped long-wheelbase A8 Hybrid sells for upwards of €85,400 – around $105,000 U.S. Given general pricing trends on both sides of the ocean and keeping in mind the higher equipment levels that Americans prefer (and generally get for cheap), the short-wheelbase model would translate to around $70,000 U.S.

Trunk space falls from the usual EPA-rated 13.2 cubic feet to roughly 10.0 cubes.

If that sounds oddly inexpensive, that's because the hybrid's price point in Germany is intended to sit right around that of a front-wheel-drive 201-hp A8 3.0 TDI V6, a markedly less powerful, less luxurious A8 than what is sold in North America. Coincidentally, though, the A8 Hybrid and A8 V6 TDI weigh the same at 4,125 pounds. Of course, here in the States, our base specification is nearly $80k for a 4.2-liter V8 Quattro model – at least until the promised 3.0-liter TFSI V6 arrives.

While the A8 Hybrid cannot beat the base diesel's fuel efficiency, it does average slightly lower CO2 emissions – an important distinction in Europe for insurance purposes. Acceleration to 62 mph for both cars is between 7.7 and 7.9 seconds. Where the A8 Hybrid significantly falls behind, though, is cargo room. The high placement of the 84-pound lithium-ion battery pack cuts significantly into trunk space. From the usual EPA-rated 13.2 cubic feet of space, chop things down to roughly 10.0 cubes using the EPA scale. This sort of lowbrow mounting strategy for the battery pack leaves us perplexed: Is the plan to have four adults aboard a large luxury four-door but leave them without enough luggage space? It's too compromising.

The A8 Hybrid could claim 37.3-mpg average city/highway per U.S. gallon.

The way the A8 Hybrid drives is understandably very numb and tranquil when done correctly and most efficiently. Push the car hard over dynamic stretches of road and you are quickly out of the car's element. This is not aided much by the front-wheel-drive platform and extremely frugal and detached-feeling electronic steering. To be fair, though, this clearly isn't a model intended for more passionate driving forays – just point it down the road and quietly go forth in the lap of luxury with little or no exterior air noise due to the 0.26 coefficient of drag.

Moments when the 2.0-liter four-cylinder switches off or on happen seamlessly, and the eight-speed Tiptronic with its integrated 52-hp electric motor is likewise creamy smooth, constantly seeking to slip into eighth gear for maximum fuel savings. Going strictly by the European cycle of efficiency ratings, the A8 Hybrid could claim 37.3-mpg average city/highway per U.S. gallon. Going by the same fudged scale, I realized an indicated 33.0-mpg average.

The cumulative result when they are both hammering together in boost mode under high throttle is 241 hp.

Helping the standard air suspension is a set of 255/45 19-inch Goodyear Eagle F1 tires, which, while good pieces, are probably not the most efficient rubber for what is otherwise a predominantly green-focused luxury car. On the other hand, the aerodynamic Turbine wheelset specific to the A8 Hybrid is good looking while aiding to lower wind resistance.

Between the 208-hp 2.0-liter TFSI four-cylinder and 52-hp electric motor, the cumulative result when they are both hammering together in boost mode under high throttle is 241 hp. The torque figure in this full-bore scenario is 354 pound-feet, much of that available from a standstill thanks to the push of the electric motor. All ancillaries that are normally run via mechanical belt drive from the 2.0-liter engine are now run electrically via various sensors that tell when things need to be actuated or not. These actuators via the high-voltage lithium-ion battery can also keep the climate control on while the engine is off in start-stop mode at traffic lights.

If we look at the details and packaging, we'd still have to go for the base diesel.

Electric-only propulsion can happen up to 37 mph under the right (and frankly almost nonexistent) conditions, though this can only be sustained for about two miles before the conventional engine ignites. In the meantime, the two power units can do their boost thing together at up to 100 mph, at which point the electric motor cuts out of the equation. Top speed is 146 mph, legal only in Germany.

Admittedly, we are pushovers for all of the big German four-door sedans because they deliver so much authority and power-of-stance. As a passenger or driving the A8 Hybrid as parsimoniously as intended (read: as luxurious transportation and not a soul-stirring sport sedan), we can still find something to appreciate in this A8 Hybrid. But if we look at the details and packaging, we'd still have to go for the base diesel – this is one hybrid that the U.S. can live without. Now, about that 4.2-liter TDI, please... 

 

 

Source: Autoblog Green

Audi to start series production of A8 hybrid in 2012

Audi A8 hybrid. Click to enlarge.

Audi will start series production of the A8 hybrid in 2012. (Earlier post.) Its 2.0 TFSI gasoline engine and an electric motor develop peak output of 180 kW (245 hp) and 480 N·m (345 lb-ft) of torque. Average fuel consumption in the EU cycle is below 6.4 liters per 100 km (36.75 mpg US); CO₂ emissions are below 148 grams per km (238 g/mile). (All figures are provisional.)

The Audi A8 hybrid reaches 100 km/h (62.14 mph) in 7.7 seconds from a standing start and has a top speed of 235 km/h (146 mph). The sedan can travel at speeds of up to 100 km/h (62 mph) on electric power alone, and cover around three kilometers (1.86 miles) with zero local emissions at a constant speed of 60 km/h (37 mph).

The A8 hybrid is a parallel hybrid. The 2.0 TFSI, which has been modified in some areas, generates an output of 155 kW (211 hp) and 350 N·m (258 lb-ft) of torque, which is available between 1,500 and 4,200 rpm. The combustion engine works together with a disc-shaped electric motor which develops 40 kW (54 hp) and 210 N·m (155 lb-ft).

The permanent magnet synchronous motor is mounted in the space usually occupied by the torque converter in front of the modified eight-speed tiptronic. A multi-plate clutch that operates in an oil bath connects or disconnects the electric motor and the TFSI engine. The fast-shifting hybrid transmission guides the torque to the front wheels; with its wide gear spread it contributes to the efficiency of the Audi A8 hybrid.

The driver has the choice of three modes: The EV characteristic map gives priority to the electric drive, while the D mode efficiently controls both the engine and the electric motor. The S mode and the tiptronic gate are designed for a sporty driving style.

The hybrid sedan has five operating states: with the TFSI engine alone, with electric drive only or in hybrid mode; recuperation and boosting are also possible. Two displays show the driver all operating modes in detail.

The lithium-ion battery, which weighs 36.7 kilograms (80.91 lb), is located in a crash-proof area in the trunk. It provides 1.3 kWh of nominal energy and up to 40 kW of power. Two different methods are used to air-cool the battery, depending on need: with air blown from the passenger compartment by a fan and via a separate cooling circuit coupled to the automatic air conditioning system. The battery is thus kept within the temperature window required for it to perform to its full potential over a wide range.

The electric motor and the compact power electronics which serve as a controller between the electric motor and the battery are water-cooled.

The Audi A8 hybrid will be one of the lightest sedans in its category. Its ASF (Audi Space Frame) body is made entirely of aluminum, while the B-pillars are of hot-shaped, ultra-high-strength steel. Weighing 231 kilograms (509 lb), it is roughly 40% lighter than a comparable steel construction.

Source: Green Car Congress

Audi TechDay e-mobility, Part 1: Q5 Hybrid, A1 e-tron range extended electric vehicle and R8 e-tron battery-electric vehicle

Audi held a TechDay in Ingolstadt focused on its efforts to electrify the driveline, and provided more details on the upcoming Q5 hybrid-electric vehicle, the A1 e-tron range extended electric vehicle and the R8 e-tron battery-electric vehicle.

In electric mobility, Audi distinguishes between two groups of vehicles: fully hybrid vehicles, driving a maximum of about 3 km (1.86 miles) under electric power; and high-energy battery vehicles for longer distances. These are the plug-in hybrids, the range extender vehicles and the strictly electrical vehicles. At TechDay, Audi spent time describing the issues and its approaches for constituent elements of different electric drive systems including electric motors and power electronics; battery pack; charging; thermal management; energy recuperation; electromechanical brakes; torque distribution; safety; lightweighting; and the use of a cell phone in the human machine interface (HMI). (To be summarized in Part 2.)

Q5 hybrid

Q5 hybrid and drivetrain. Click to enlarge.

The Q5 hybrid quattro, which goes into production in 2011, is the first hybrid model from Audi with two drive systems. Its gasoline engine, a 2.0 TFSI, and its electric motor are mounted directly behind one another as a parallel hybrid system, with system output of 180 kW (245 hp) and 480 N·m (354 lb-ft) for sporty dynamics. The mean consumption in the normal cycle (NEDC) is limited to less than 7.0 liters per 100 km (33.6 US mpg), corresponding to CO₂ emissions of less than 160 grams per km (257.5 g/mile).

The new top model of the Q5 series accelerates in 7.1 seconds from 0 to 100 km/h and attains a top speed of 222 km/h (138 mph). In electric mode the hybrid SUV can cover a distance of up to three kilometers (1.86 miles) at a maximum speed of 60 km/h (37 mph).

Q5 hybrid motor. Click to enlarge.

The turbocharged gasoline direct injection 2.0 TFSI in the Audi Q5 hybrid quattro has a displacement of 1984 cc (121 cu in), with output of 155 kW (211 hp) and maximum torque of 350 N·m (258 lb-ft) permanently available at 1500 to 4200 rpm. The Audi valve lift system (AVS) further increases power, torque and efficiency by switching the stroke of the exhaust valves between two stages depending on the load and rpm.

The 2.0 TFSI has been overhauled in some respects for use in the Audi Q5 hybrid. The drive of the ancillary units has been dropped, and the crankshaft bearing and fine tuning of the turbocharger have been adapted to the specific demands. A secondary air system at the cylinder head makes sure that the exhaust gas treatment cuts in particularly quickly. Integrated in the engine control unit, the hybrid manager controls the efficient change and smooth transitions between the operating modes, and was fully developed by Audi alone.

A largely modified eight-speed tiptronic serves the power transmission without the aid of a torque converter. Its place is taken by the disk-shaped electric motor, combined with the multi-plate clutch operating in an oil bath that it couples and decouples the electric motor and the TFSI. The hybrid gear unit contributes significantly to the efficiency of the Audi Q5 hybrid— its eight gears are widely spaced. When the 2.0 TFSI is turned off, an electric pump maintains the oil pressure in the hydraulic system to safeguard the convenient start-stop feature.

Cooling systems. Click to enlarge.

The power electronics, connected to the battery and the electric motor by high-voltage cabling, is located in the plenum chamber of the engine compartment. Cooling is provided by a separate low-temperature water-filled circuit. The component includes a DC/DC converter that couples the electric consumers in the 12 V electrical system with the high-voltage network.

A permanently excited synchronous machine serves as an electric motor, as a starter and—during deceleration—as a generator. It outputs up to 33 kW (45 hp) of power and 211 N·m (156 lb-ft). The electric motor is integrated in the cooling circuit of the engine.

Audi Q5 Hydrogen Fuel Cell Concept
Audi is also studying the potential of fuel cell drive systems for long-range electric mobility—the Audi Q5 HFC (Hybrid Fuel Cell) concept car has this technology on board.
The concept car relies on synergism and consequently utilizes many technical components from the future hybrid models. Two high-pressure cylinders store hydrogen under a pressure of 700 bar. The polymer electrolyte membrane (PEM) fuel cell outputs 98 kW (133 hp).
The lithium-ion battery serving hybridization has an energy content of 1.3 kWh. The drive is provided by two electric motors close to the wheels; the motors have a combined top output of 90 kW and a torque of up to 420 N·m (310 lb-ft).
The efficiency of the fuel cell drive lies above 50% in a wide operating range.

A lithium-ion battery system, weighing 38 kg (83.78 lb), serves as the energy store for the electric motor of the Audi Q5 hybrid quattro. The compact unit with its 26 liter (6.87 US gallon) capacity is positioned in a crash-safe area under the loading floor, with hardly any detriment to the luggage compartment. The battery consists of 72 cells; at 266 volts its nominal energy is 1.3 kWh and its output 39 kW.

The lithium-ion battery is air-cooled in two ways, depending on the requirement. At low-temperature load, it draws temperate air from the vehicle interior by way of a fan. If its temperature exceeds a certain limit, a separate refrigerant circuit is activated. It is coupled to the main climate control system of the vehicle and uses a separate evaporator. This heavy-duty active cooling system distinguishes the Audi Q5 hybrid quattro from many other hybrid vehicles, Audi noted, and makes a key contribution to the high electrical availability of the hybrid system.

As a component of the modular longitudinal platform, the powertrain of the Q5 hybrid quattro can also be used in other Audi models with longitudinally mounted engines. They include the new Audi A8 as well as the A6 and the A6 Avant of the next generation.

A1 e-tron

A1 e-tron technical data. Click to enlarge.

The Audi A1 e-tron is a range extended electric vehicle. The synchronous motor of the Audi A1 e-tron is mounted transversely in the front, with its low installation benefiting the center of gravity. It has a continuous power of 45 kW (61 hp), with a torque of 150 N·m (111 lb-ft) already available from a standstill. The peak performance lies at 75 kW (102 hp), the maximum torque at 240 N·m (177 lb-ft). Acceleration from 0 to 100 km/h takes 10.2 seconds.

The electric range is similar to that of the e-tron Spyder, about 50 km (31 miles). A small rotary engine in the rear serves as a range extender. In range mode the A1 can cover a further distance of 200 km (124 miles).

The torque flows to the front axle via a single-staged transmission flanged to the electric motor. The selector lever stems from the series production model, following the appropriate adaptation. The modes are D, R, N and Range—on this level the range extender is activated depending on the applied operating strategy; the electronic management system cuts in the extender with smooth transitions. The current load requirement and the energy level of the battery are the most important factors.

In the engine compartment next to the electric motor are the power electronics, which control the electric traction. The DC converter coupling the 14 V electrical system to the high-voltage system, the switching unit for protecting the high-voltage components and the charging module are also accommodated in the front end.

Shaped like a T, the battery pack of the Audi A1 e-tron is located underneath the rear part of the center tunnel and under the rear seats. The lithium-ion battery, operating at 270 volts, has a normal energy level of 12 kWh, and is water-cooled to stay within an optimal temperature range. The socket for the standard charge plug is located behind the rings in the single frame of the Audi A1 e-tron.

A fully discharged battery requires less than three hours’ charging from a 230 V grid; a 380 V high-voltage current reduces the time to less than an hour under optimal conditions. A display next to the plug-in connection shows the remaining charging time and the charge state. This value and the current range also appear in the driver's information display of the instrument cluster.

During travel the large electric motor driving the A1 e-tron can convert the deceleration energy into electric current and feed it back to the electrical system, by operating briefly as a generator. The energy return flow begins once the driver releases the accelerator.

The extent of the recuperation is controllable in five stages by rocker switches on the steering wheel. At stage 1 the deceleration is slight, and at stage 5 considerable. In urban traffic the A1 e-tron can recover through recuperation almost a third of the energy needed for driving. When the rocker switches lie at 0 and the driver releases the accelerator, the vehicle needs no energy at all—it simply glides.

A small single-disk rotary piston engine serves as the range extender on board the Audi A1 e-tron. It has a chamber capacity of 254 cc (15.5 cu in) and constantly runs at 5000 rpm in its optimal efficiency range. The rotary piston engine drives a generator that produces up to 15 kW (20 hp) electrical charging power.

The great strengths of the rotary piston engine are its vibration-free and practically noiseless operation, small dimensions and the extremely low weight. Including the generator, the entire assembly group weighs about 65 kg (143 lb). This weight already includes the special power electronics, the intake, exhaust and cooling systems as well as the acoustic encapsulation and the auxiliary frame.

According to the draft for standardization for determining the consumption of range extender vehicles, the rate of fuel consumption by the Audi A1 e-tron is 1.9 liters per 100 km (124 mpg US)—a CO₂ equivalent of 45 g per km (72 g/mile). The fuel is supplied from a tank with a capacity of 12 liters (3.17 gallons US).

The ancillary units of the A1 e-tron are electrified. A high-voltage refrigerant compressor operating according to the current power requirement drives the air conditioning system, for greater efficiency compared with conventional concepts. The power steering operates electrohydraulically as in the series production model. The hydraulic brake system includes a brake servo, with the vacuum supplied by an electrically operated pump, also demand-controlled.

In 2011 Audi will be joining three project partners—the energy supplier E.ON, the Munich public utility company and Munich Technical University—in launching a fleet test with the A1 e-tron. (Earlier post.) By the middle of the year the first vehicles should be hitting the road in the Bavarian capital, while at the same time 200 new charging stations will become operational.

R8 e-tron

The Audi R8 e-tron is a high-powered sports car with a battery-electric drive. Its four motors—which can be individually actuated—provide a total power of 230 kW (313 hp). The four asynchronous motors—two each on the front and rear axles—make the Audi R8 e-tron a quattro. Power is transmitted to the wheels via the single-staged transmission and short input shafts. With up to 4,500 N·m (3,319 lb-ft) torque at the wheels available from a standstill, the R8 e-tron accelerates from 0 to 100 km/h in 4.8 seconds.

The large, fluid-cooled lithium-ion battery and the power electronics lie directly behind the passenger compartment. The result is an optimal center of gravity and a load distribution of 42:58 between the front and rear axles—just like the series production R8 with its 5.2 liter FSI.

The rechargeable lithium-ion battery installed in the Audi R8 e-tron consists of single cells with a high energy density connected in parallel and in series, and ensures a high output. The 550 kg (1,213 lb) battery stores 53 kWh of energy, with the usable share amounting to 42.4 kWh. In the final design stage of the Audi e-tron, the battery will enable a range of about 250 km (155 miles) when operated in the NEDC cycle.

For recharging the battery a household current with 230 volts suffices; the process takes six to eight hours for a fully discharged battery. A high-voltage current will reduce the charging time to about two and a half hours.

The distribution of the electric drive torque in the R8 e-tron distinctly favors the rear axle. Like the standard Audi R8, about 70% of the power acts at the rear in regular operation, with the remaining 30% going to the front wheels. Should slip occur at an axle, this balance changes in a fraction of a second.

The R8 e-tron also manages the lateral dynamics through its four motors. They allow torque vectoring, the selective acceleration of individual wheels and therefore active distribution of torque. Understeering and oversteering can be compensated by small power boosts and brake interventions. The electrically driven high-powered sports car retains neutrality even at maximum lateral acceleration.

The running gear employs double triangular control arms at the front axle and trapezium links made of forged aluminum components at the rear axle—a configuration that has proven its merit in motor sports as an optimal layout for high dynamics, maximum precision and exact intrinsic steering behavior. Notwithstanding the firmness of the springs and shock absorbers, they still afford good comfort. The rack and pinion steering with its direct gear ratio provides finely differentiated feedback. The steering is electro-mechanically assisted depending on the speed. The Audi R8 e-tron rolls on 19-inch wheels.

Audi will be bringing a limited edition of the R8 e-tron to the roads in late 2012. It will be built at quattro GmbH in Neckarsulm, which has extensive experience in the construction of exclusive sports cars.

Source: Green Car Congress