Just a few months after launching the Panamera petrol hybrid, Porsche is serving up an alternative maximum efficiency GT: the Panamera Diesel. It can, says Porsche, cover 745 miles on its 80-litre tank. If you’ve got a capacious bladder, an optional 100-litre tank is set to be an option too.
The Panamera Diesel goes on sale from August 2011, and, like the hybrid, is available only in rear-wheel drive with an eight-speed Tiptronic torque converter auto, not the PDK dual-clutch transmission that’s offered on all other Panameras.
How do the figures of the new Porsche Panamera Diesel compare with the hybrid?
The diesel puts up a strong fight: it’s 100kg lighter, emits 172g/km CO2 (or 167g/km on the optional low rolling resistance tyres) compared with the hybrid’s 159g/km, and returns 43.5mpg to the hybrid’s 41.5mpg.
In terms of performance, the Diesel’s 247bhp and 406lb ft are outclassed by the hybrid’s 375bhp and 428lb ft, while the Diesel’s 6.8sec 0-62mph time and 150mph top speed are shaded by the hybrid’s 6.0sec and 167mph.
Crucially, though, the Diesel is far cheaper, its £62,134 playing the hybrid’s £86,476.
In terms of price, it sits one rung above the entry-level V6 petrol. The V6 petrol figures are: 6.3sec 0-62mph, 162mph, 31mpg, 296bhp and 295lb ft.
Why's there no four-wheel drive? Why no PDK transmission?
The Panamera wasn’t initially conceived as a diesel, and the 3.0-litre diesel and gearbox are lifted directly from Audi. Other four-wheel drive Panameras have the transmission passing through the sump, but the Audi hardware wasn’t designed to do this. It works in the Cayenne Diesel because the same engine sits higher, and the running gear can pass below it. But in the Panamera, it’s just not possible.
The new 3.0-litre twin turbo Audi TDI engine with 309bhp wasn’t used either: the Panamera’s engine sits as far back in the engine bay as possible to enhance driving dynamics, and the new Audi unit simply couldn’t be packaged in the same way.
How does the Panamera diesel drive?
The diesel is certainly smoother and lustier than the last-generation unit that debuted in the Cayenne (and it’s usefully 20kg lighter too), pulling strongly from just after 1500rpm. And at motorway speeds on low throttle loadings it’s actually quite difficult to tell you’re in a diesel at all, even with the low levels of wind- and road-noise that you experience in a high-speed Panamera. But work it harder and you’re in doubt that you’re being propelled by a compression ignition unit, and it’s no real fun to wind out either, straining once it’s out of its narrow 1750rpm to 2750rpm torque sweet spot. It’s at it best being stroked along at low to mid speeds, where it offers up easily accessible shove.
The gearbox is a similar story – it’s smooth if a little dozy in Normal mode, although the close ratios do their best to keep you in that optimum torque zone. Switch to Sport and there’s extra responsiveness and an eagerness to hold ratios, but, really, you’ll need full-on Manual mode to really enjoy a drive and, happily, the Tiptronic auto works well here, responding obediently to shift commands – if not as snappily as a PDK transmission – and acknowledging multiple shift inputs: pull the paddle three times in very quick succession when you’re in fifth and you’ll get second every time.
Like PDK, you also get a standard stop/start system, which worked on most – though not all – occasions.
What about the handling?
The steering is really good, being nicely weighted with a feeling of linearity and purity. Our car came on 18-inch wheels with the optional three-way dampers, and the results were mixed: the ride is quite firm even in the softest mode and the body control feels excellent, but there’s a delayed response in faster turns between your steering input and the chassis following it. Select the second damper mode and this is greatly reduced, yet the ride comfort isn’t much worse – if you’re driving quickly, you’ll need at least this second setting to feel confident. Unusually, however, harder road driving does justify use of the third damper setting – that’s an over-firm, track-only setting in most cars.
The Panamera Diesel is far from a bad car to punt along a flowing, fast road, yet somehow the manual Panamera V8 petrol is a much more cohesive, more satisfying thing to extract the maximum from.
The Panamera Diesel is, by and large, a success. The engine is smooth and willing, the economy figures appealing, and the interior is a lovely place to be. However, the general flaws of the Panamera are still present: it’s not the easiest thing to see out of (either to judge the kerb, or to reverse), the rear accommodation and boot is easily shaded by a Mercedes S-class, and in the case of the Diesel, the handling isn’t as satisfying as, say, the V8 manual.
A Cayenne is cheaper, more spacious and still a decent drive, so if you’re tempted to go for a Panamera test drive, make sure the dealer gets you in a Cayenne too. Whatever your preconceptions, you might just prefer it.
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