Mainland Europe's car population is 80 percent diesel. With less taxation, greater fuel economy and lower emissions to accompany an enjoyable torque-laden drive, diesel makes way more sense than hybrids. German manufacturers Audi, BMW, Mercedes-Benz and VW are now selling diesel-powered models in the USA. Even though the market share for these models is currently not that impressive, it looks like they may soon be joined by Porsche.
There is no timetable to speak of, as Porsche is still in the throes of finding a business case for it (according to Porsche's research, roughly 10 percent of American customers would prefer their next vehicle to be diesel-powered; the company wants to see that figure rise to 20), but a diesel Cayenne would be a good fit over here. As a way of sniffing the wind, Porsche shipped a model to California (the state that's chief of the smog police).
Nestling in the engine bay is an Audi-sourced 3.0-liter turbocharged V6. Peak power is a nice enough 240 horses, capable of galloping this vehicle to a top speed of 133 mph. However, torque is the star of the diesel show. With an advantage of 37 lb-ft over the Cayenne S, a muscular 406 lb-ft chimes in at just 2000 rpm-enough to send this beast flying from standstill to 60 mph in 8.3 seconds. That's with a Tiptronic S automatic transmission. And since many Americans like to use their SUVs for towing, they will appreciate being able to haul a 3.5-ton trailer.
Because the Cayenne diesel has not yet been homologated for American roads, there are no EPA figures, but here are some interesting numbers: Average fuel consumption is claimed to be 25.3 mpg; range for the 26-gallon tank is up to 620 miles. Porsche is claiming 28 percent less fuel consumed than a similarly powered petrol V6 Cayenne.
The roads in and around Los Angeles are in the same sorry state as Russian dental health during the Cold War. The Cayenne makes them seem like brand-new veneers. Ride quality is as near to perfect as dammit, while the engine is quiet, smooth and punchy, with immediate throttle response. Even with some serious right foot, there's more of a gruff roar than a clatter. If the American driving style is made up of steady cruising with the occasional prod on the accelerator to pass other cars or get up to freeway speed, then this kind of engine is ideal. It has a loping quality.
As if that weren't enough, the six-speed transmission selects each ratio with an almost imperceptible snick. Incidentally, this is a 2010 model and although the dash design looks pretty much unchanged, the quality of materials feels and looks more expensive.
By now, even the most hard-core Porsche purists have come to accept the Cayenne. If it means the company can make a heap of cash that in turn enables it to produce GT2 and GT3 models, then who are we to complain about a perfectly nice luxury SUV? By that token, it's not much of a stretch for die-hard petrolheads to get on board with diesel. From the emissions/consumption point of view, it's a no-brainer. And having such a surge of torque makes this Cayenne worthy of the Porsche badge on its hood.
Trouble is, there's a bigger-picture issue here. Will Americans abandon their diesel prejudices? Can they? Diesel used to be disgusting, noisy and slow-about as far from Porsche attributes as it's possible to get. And even though the general public is notorious for having a short memory, earlier experience must have been traumatic enough for the repulsion to linger.
Here's an idea: Why not re-brand it? Call it Euro-fuel or something (the French don't call their fries French fries and the English have no idea what an English muffin is, so America has hi-jacked European descriptions before with some success). Now, if only there was a way to dispense it that didn't involve smelly hands and slippery floors.
It's all about CAFE standards, right? Federal corporate average fuel economy legislation means every car maker wanting the privilege of selling its wares in the States will have to comply. Hence all the hybrids, EVs, diesels, etc. But not so fast... and maybe not so cynical.
Here's the thing: Porsche customers are asking for hybrids. As unsure as the company is of a business case for diesel Cayennes, it's certain enough to produce a hybrid Cayenne that goes on sale in North America in spring 2010 with a ballpark price of around $70,000. Porsche will also make noises about "social responsibility" but, hey, whatever gets its engineers through the night when they are dreaming about what to do with all those dead nickel metal hydride battery packs. Perhaps they might also take into account the working conditions of miners and what impact a nickel mine has on its surroundings. But at some point in the final shakedown, the result is less fuel being used and less emissions from vehicles.
Because it's made by Porsche, the Cayenne S Hybrid (the S denotes the same trim and comparable power levels to a conventional Cayenne S) bristles with smart technology, including an eight-speed automatic transmission-not a CVT like so many boring hybrids. This is certainly not a case of paying Toyota a licensing fee and then adapting its system. For instance, the Lexus RX hybrid uses an electric motor to power its rear wheels. Porsche's electric motor adds 38 kilowatts of heft to a 333-hp 3.0-liter V6 (sourced from Audi and utilizing direct fuel injection) which is then sent to all four wheels. Hence the lack of lithium ion batteries. They're OK for puny little 17-kilowatt motors, but Porsche has to have the punch from a nickel metal hydride pack.
Altogether, the system puts out 374 hp and a substantial 406 lb-ft of torque, good enough for zero to 60 mph in 6.5 seconds. Top speed is 149 mph. Yet Porsche says fuel savings are 50 percent over a gasoline-powered V6 Cayenne. When driving in the real world, the combustion engine is only working for about 44 percent of the time. Brake regeneration takes up 12 percent, electric-only locomotion is 26 percent, and the stop/start feature accounts for the remaining 18 percent. Average consumption works out to around 27 mpg, with a range of 680 miles.
It works. Over an admittedly short test distance, the Cayenne Hybrid is an extremely pleasant thing to pedal. Trying to hit that magic 680 number should feel like no chore whatsoever. It has all the capability and class expected from a high-end German SUV (the prototype used in this test is worth about one million euros; that's pretty high-end).
Just like the diesel version, this one is serene, changing gears as if by magic. It can run up to 32 mph in electric-only mode. On downhill stretches, the Cayenne hybrid has a freewheeling function: the engine turns off, ready to re-ignite at the touch of an accelerator. Same story at traffic lights and other stop/go situations. This function operates with the same ninja-like subtle efficiency as the gearbox. And the brakes do that usual hybrid regeneration thing. The brake pedal feels super-sharp the first couple of presses, but it's easy to get used to after a few miles. Which is more than can be said of the steering. Unlike the rest of the Cayenne range, this is electrically assisted. It doesn't have quite the feel or weight expected from this marque.
So here's the other thing: the Cayenne Hybrid S is a nice Germanic, generic SUV, but it doesn't really feel like a Porsche, whereas the diesel Cayenne does. Does it matter? Probably not, for a number of reasons. A Porsche badge and a hybrid badge on the same vehicle is some soccer mom's ideal car, and it could also impress the chaps at the golf club. The real enthusiast would have bought a 911 anyway. Why hasn't Porsche gone the whole hog and made a diesel hybrid? Because the stop/start function is a lot jerkier with a diesel engine, but there could well be one in the future.
And then there's the whole VW/Porsche who's-buying-who debacle. If VW's other cars are more frugal and allow the company to comply with CAFE regulations, a hybrid (or diesel) Cayenne may be rendered moot. There are even rumors of VW canning the Cayenne and the Panamera sedan completely if it becomes the owner of Porsche. If that were the case, what would it do for the luxury segment, revive the Phaeton?