Friday, October 26, 2007

2008 Audi Q7 3.6 Hybrid Prototype

Audi Q7 hybridAudi Q7 hybrid

There’s no doubt that hybrid electric drives are an important part of the American automotive market. Though diesel technologies now encompass more than 50% of the European car market and are expected to grow in popularity here in the USA as new models become available, there’s no denying that hybrids are well entrenched as the frontrunner in green technologies in this market. Audi knows this, and is moving to make its own production hybrid models available. In fact, the company is so close in development that they’ve allowed a limited number of press to sample an early prototype fitted to a Q7 3.6 – the same car we were able to drive just last week in San Francisco, California.

Audi first started experimenting with hybrid technology in 1990 with the 100-based Duo Concept. More recently, a Q7 Hybrid Concept with production in mind was shown at the 2005 Frankfurt Motor Show, and just this week the company revealed the compact MetroProject quattro concept with a similar system for compact transverse engine applications.

With this sort of long flirtatious history with hybrids, it’s easy to see Audi’s continually increasing movement to embrace the technology. This movement is expected to spawn the first full production hybrid Audi, likely the Q5 and specifically for the American market, by the end of next year. More hybrid offerings are expected to follow

There may be no Q5 yet available for sampling by those outside of the restricted gates in Ingolstadt, but this prototype Q7 3.6 Hybrid was close enough to sample what Audi is doing.

This particular prototype uses an electric motor/generator placed between the engine and gearbox. An electronically controlled clutch manages interaction between the two power units.

The actual setup is fairly invisible to the casual consumer. Pop the hood and you’ll notice some differences, components clearly visible. At the rear, the Q7 Hybrid’s nickel-metal hydride battery can also be found underneath the deck lid in the trunk.

Unlike more commonly seen hybrids on the market today such as the Toyota Prius, the Audi is what Ingolstadt refers to as a “full hybrid”, having the flexibility to run on either electric power or spark ignition alone, as well as to utilize a combination of the two.

Like many hybrids today, the Audi system uses regenerative braking, which allows the car’s batteries to be charged when kinetic energy is converted to electrical power during coasting or braking that can later be used for forward propulsion.

Fuel consumption savings are to be expected. Audi benchmarks the performance of their own diesel models as the goal for consumption by petrol-based hybrids. This Q7 uses the 3.6 FSI, arguably not as efficient as the 3.2 FSI with Valvelift we’d expect to see used in the B8-based Q5 Hybrid, but the 3.6 Q7 is still reported to be 23% more efficient than its road-going non-hybrid equivalent. Audi reports 24 mpg combined for this setup – only 1 mpg less than reported for the Q7 3.0 TDI.

While driving, the system can be monitored via the Audi’s MMI screen. A diagram of the car shows the level of power stored in the battery via eight green bars while it also indicates the current source of power, be it the 3.6-liter engine or the batteries.

Our Q7 prototype also featured a German option button labeled “E-Fahren”, which alllows the driver to switch from hybrid to full-electric mode. Toggling to full electric, it’s easy to see that the Q7 wouldn’t get more than a few miles on the limited battery power it has. Experiencing stop and go traffic in the heart of San Francisco, those eight green bars disappeared quite rapidly.

That said, one would suspect a rural driver with a very short commute could travel mostly or even solely on electric power if their drive were short enough. If Audi paired this with a home plug-in module or a sunroof solar panel like that of the A8 but making use of the Q7’s expansive Open Sky setup, one might even repeatedly operate the car on electrical power with a short enough commute.

With just one motor/generator, the Q7 Hybrid cannot utilize its regenerative braking in creeping situations like our rush hour city center traffic. If the motor is being used for propulsion, it cannot also be generating. Kinetic energy is only captured when fully braking and not while creeping along with partial brake and partial propulsion.

In general, the driving experience is not far from a gasoline equivalent save the obsession with watching the car’s power management diagram – a habit that seems to afflict Prius owners as well. We did notice some roughness of transition when the car transferred from full electric power to the point where the gasoline engine would fire up. We’d guess and hope that this will be much more undetectable when experienced in a full production model.

Besides the obvious fuel savings, there are added benefits to this type of “parallel hybrid” system, where the two modes of power are utilized separately or simultaneously. Audi owners with a priority on performance will be pleased to know that the electric motor can and is used to augment the power of the Q7’s engine, making it faster than the standard Q7 3.6. The added battery power is good for an extra 52 hp under full throttle. Audi claims a 0-60 mph run for the hybrid to be 7.4 seconds. That’s .8 seconds faster than the 3.6 FSI and a full second ahead of the Q7 3.0 TDI.

Another benefit to the system’s parallel nature is the modularity of the design, meaning more flexibility on the number of models that can be fitted with such a setup. Considering what we know already based on the existence of a Q7 Hybrid and the Metroproject quattro Concept, along with the plans for launch in a Q5, one would assume Audi is close to having a hybrid drive system that could fit every model. This would include the transverse cars such as the A3, TT and upcoming A1, to the longitudinal offerings of A4, A6, A8 and Q7. Even the mid-engined R8 may not be much of a challenge to fit the hardware.

With the flexibility of this hybrid hardware combined with Audi’s core competency in diesel, one would think the natural conclusion would be for the company to produce a diesel hybrid model. In fact, Audi’s own 1996 Duo III Concept modeled just such a drivetrain.

Unfortunately, Audi executives say they aren’t considering a pairing of diesel and hybrid technologies any time soon. They point to the considerable cost of each of the two technologies that would make for a considerable premium in cost for such a model. Putting the two together in one vehicle would likely result in a diesel hybrid costing well more than their high performance equivalents.

Think of an A4 3.0 TDI Hybrid as likely to cost somewhere above the S4 and maybe closer to that of the RS 4. Granted, an augmented 3.0 TDI might not fall far from an S-car’s performance levels. Still, putting such a product into the market is most certainly a gamble and whether there is a wealthy clientele as willing to spend on being green as they are to go fast will determine if any product such as this would ever be built. For now, Audi says no, though we suspect demand by the public could most certainly help change those opinions internally. And, rival Mercedes-Benz might help cultivate that demand, having today debuted its own Bluetec Hybrid diesel concepts based on C and S-Class models and having divulged that the Stuttgart-based car company fully intended to put a diesel hybrid into production.

For now, Audis near-term hybrid plans are best envisioned by looking over this otherwise nondescript Q7. Without the graphics, the car would blend easily into traffic and motor luxuriously along with significantly better fuel economy – something we suspect green-savvy Californians would be more than happy to consider in their next car.
Source: fourtitude

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