Should Porsche Make Cars That Even Hint At Driving Themselves?

2014 Porsche ACC InnoDrive

We have to remind ourselves to breath deeply at these high-tech junctures in the road. Porsche is still first and foremost a remarkable sports car company that we all love and adore for so many reasons. In recent years, yes, Porsche has challenged all of us with some product and tech moves that have caused a groundswell of debate. But the Stuttgart-Zuffenhausen based company still continually makes the lion's share of enthusiasts dream big.

We have just been brought to the company's hardcore research & design center in Weissach in the verdant farm country just outside of Stuttgart to drive special Panamera S test mules equipped with the most recent iteration of an ECU-software development that Porsche knows is going to make people like us fret. Until we actually experience it first hand.

Adaptive Cruise Control is a pretty quotidian option these days, especially on larger Porsches that get driven regularly in busy highway traffic. It's a good idea that's been serving owners faithfully since its introduction.

But we've just tried the next phase in ACC development, called ACC InnoDrive, short for Innovative Drive. It's officially part of the Intelligent Drive Strategy sub-group within the Porsche Intelligent Performance umbrella. The InnoDrive system takes ACC into areas of our driving lives that a Porsche shopper would never have imagined from the brand just 10 years ago. Mercedes-Benz, Audi, maybe BMW, you bet. But the winningest company in racing?


Porsche AG has clearly changed and broadened its set of objectives. Over 70 percent of Porsches sold today are not the low-lying sports cars we fell in love with years ago. Most are larger, taller, heavier cruisers and commuters, and they are full of high-tech aides. Soon, the Cajun small crossover will arrive (pronounced by the Germans as "KA-yoon"), which will knock Porsche's sports car sales percentage down to 15 percent or, eventually, just 10 percent of the annual total.

No sense whining about the new Porsche AG then; that train has long since left the station. ACC InnoDrive is just the next big step in embracing this reality.

2014 Porsche ACC InnoDrive front view2014 Porsche ACC InnoDrive rear view

Instead of simply gauging distances between cars in highway traffic and thereby being an active safety feature, ACC InnoDrive bridges the gap between leaving it at that and brainstorming your entire mapped-out route – including those pesky elevation changes and curve radii – in order to ensure optimized fuel usage. This goes way beyond cleverly dealing with the risk of rear-ending the Chevrolet in front of you.

The day's program had us drive our Panamera S – with an additional 16-megabit ECU bolted into the cargo floor – over a typically varied 15-mile loop of two-lanes starting and ending at Weissach. We took three stabs at it, all the while a flash card absorbing how we were doing and graphing it. The first loop was normal with no ACC help, a mode the team refers to as "manual" (indicated as such also in the two PowerPoint screen grabs in the gallery for this story). Loop Two was with ACC InnoDrive in default Comfort mode, and the third loop was using the program's Dynamic and/or Dynamic Plus modes. If you look at those graphs and charts, our particular test car is represented by the dark blue symbols.

2014 Porsche ACC InnoDrive2014 Porsche ACC InnoDrive

The normal "manual" first loop was quite.... err... normal, and we didn't work every moment to milk all the efficiency from the fuel supply that we could have. The second loop was destined to produce the greatest savings if we were to believe what the engineering team on the project was telling us. On this go-round, we pushed the lower-left stalk on the steering column forward and awaited the "ACC" acronym to light up and the graphics to go orange. Then we summoned Comfort mode on the test mule's added touchscreen and removed our feet from the pedals. Off we went and, yes, it was eerie at first.

The chief challenge to writing the algorithms for such automated sat-nav integrated features on any car is that the vast amounts of digital mapping and detail needed often doesn't exist or the data isn't readily available for any but the largest multi-lane roadways. In fact, for this set loop in Germany, the system carried the data only for this loop's two-lane roads. The basic ACC continues its task, while InnoDrive uses the historic and very detailed data from the test route, anticipating all speed limits along the way, as well as anticipating all elevation changes and curves en route.

2014 Porsche ACC InnoDrive rear cargo area2014 Porsche ACC InnoDrive2014 Porsche ACC InnoDrive2014 Porsche ACC InnoDrive

ACC InnoDrive essentially treats your whole planned route as a set drive corridor to be optimized in order to maximize all efficiencies. The basic sensation in full-automatic mode with the PDK transmission is that your path is as smoothly executed as possible. Via engine, transmission, and brakes, it always knows when to decouple from the engine and leave it to idle while cruising, thus sapping less power. It engages and disengages the clutch seamlessly, monitors acceptable lateral acceleration for your chosen driving style, and uses the throttle with far more subtle variations than humans are capable. We felt all of this going on during loops two and three, and, at the very least, it was fascinating. A chief additional objective here, besides efficiencies in general, is to finally be able to regularly meet all of the EPA numbers publicized on any car's Monroney sticker.

It all takes a lot of getting used to, but the gains in efficiency (and thus drops in emissions) in our case were at least 10 percent better versus the so-called manual mode, whether we were in Comfort or Dynamic modes. Engineering team leader Tobias Radke tells us, "Besides more widespread and available digital mapping and a more detailed GPS feed, cars that opt for ACC InnoDrive will need an additional camera/sensor up behind the rearview mirror to complement the main unit in the grille." In short, there's a lot of software activity going on with the added ECU at every instant along our drive.

2014 Porsche ACC InnoDrive2014 Porsche ACC InnoDrive

How did it make us feel? The six-member project team overseen by Matthias Lederer and Martin Roth insist that Porsche sportiness will not be sacrificed in the search for better energy management. This effort started back in 2007 and will not be made available on any Porsche until at least 2014 (probably for the next Panamera), so there is time to perfect the technology and get the message out. It all sounds wonderful and functioned as planned, and it is optional equipment not standard, but we nonetheless had to ask that spiritual burning question: How far will Porsche go in taking the driving decisions out of our hands (and feet)?

If our third Dynamic/Dynamic+ loop is any indication, ACC InnoDrive presents potentially huge possibilities for the everyday Porsche driver. Keeping our feet off the pedals was heart-stopping at moments, but the system worked remarkably well – right down to a full stop in busy traffic – and after a while, we got more in sync with it all. Porsche has tested ACC InnoDrive on a 911 Carrera already, too, so how this would be suitably folded into the marque's sports cars is definitely being scrutinized heavily. Believe us: Porsche made it clear that it knows the delicate frontier it is exploring here.

2014 Porsche ACC InnoDrive

Once ACC InnoDrive is fully refined, your feet will be able to stay off the pedals nearly completely whenever you so choose, particularly over your regular everyday routes in the system's memory. And the entire setup can be overridden at any time, of course, so it's not witless driving per se. It's just difficult for us to know exactly how to quantify it right away, as it might well become available on Porsche's entire line of vehicles. But we have three years until we start finding out.

As a side observation, ACC InnoDrive would surely be an excellent match for maximizing and perfectly calculating any route and the exact range possible for an electric vehicle, as it would put a quicker end to range anxiety fever.

And fear not; as engineer Roth said to us, "We will not touch the steering, trust us. That hands-on aspect is key to the Porsche experience."

Expect more debates over this.