Power has once again taken a back seat to fuel efficiency at Porsche, with the new Cayman range following in the footsteps of the 911 by providing a bigger leap in fuel efficiency than power output.
And the German car maker says the shift in emphasis will continue.
The man in charge of engine development for the Cayman, Jurgen Kapfer, says the company is looking at further ways of improving fuel efficiency across its range, with smaller capacity, turbocharged versions of its flat six engines the most likely option.
But he says there will be no hybrid or diesel version of the company’s sports cars and he ruled out a move to four-cylinder turbo power.
“If you look at the engine bay of a Cayman or 911 it is like a tailored suit. There is no room. A four-cylinder engine would actually be longer than a flat-six,” he says.
He says hybrid engines wouldn’t be practical for a sports car until lighter lithium-ion batteries could be used.
“There are too many weight penalties. It would upset the balance of the car,” he says.
He also discounted turbo-diesel engines for the Cayman and 911 range, claiming high-revving engines were part of a sports car’s DNA.
“With a diesel, there is nothing after 5000rpm,” he says.
Kapler says “there is plenty of room” for development of the current series of engines in the Porsche sports car line-up, hinting that smaller-displacement engines were one option for retaining performance while meeting increasingly stringent European Union regulations on carbon dioxide emissions.
“We had the last range of engines for 12 years and were always improving them. We have only just started developing the new range,” he says.
Porsche has taken the unusual step of introducing four all-new engines during a mid-life model upgrade.
And for a brand that has always sold on power and performance, the emphasis on fuel efficiency is a stark reminder of the changes engulfing the car industry.
The two new Cayman engines, smaller displacement versions of those in the 911, come just three years into the car’s product cycle, demonstrating the company’s resolve to reduce its environmental footprint.
Fuel consumption on the base model’s 2.9-litre six is down by up to 11 per cent depending on the transmission choice, while consumption on the S models is down by up to 16 per cent.
The double-clutch, automated-manual version of the base Cayman uses just 8.9 litres per 100km (9.2L/100km in manual form), while the Cayman S uses 9.2L/100km (9.6L/100km in manual).
The fuel efficiency improvements to the base Cayman engine come despite a larger displacement engine (up from a 2.7-litre unit on the previous model) and an 8 per cent power increase.
On the S model, displacement has remained the same, but power is up by 8 per cent.
While the engines have been overhauled, with the Cayman S getting direction fuel injection for the first time, the secret to the improved fuel consumption lies partly with Porsche’s PDK seven-speed, twin-clutch automated-manual transmission.
But Porsche’s pursuit of frugality has extended to the tyres, which have new lower rolling-resistance rubber. The PDK version of the Cayman is also 15kg lighter than the previous model: the engine is 6kg lighter, while the transmission is 9kg lighter, which also helps to improve the car’s weight distribution.
The new transmission, which debuted on the 911 earlier this year, is also the reason why Porsche can claim improved acceleration figures for the Cayman range.
The Cayman S, fitted with the PDK and Porsche’s optional launch control feature, now takes just 4.9 seconds to complete the 0-100km/h sprint, a tenth of a second quicker than the manual version. The base model completes the sprint in 5.5 secs with PDK and launch control.
The manual transmission now has six gears instead of five. Porsche expects fewer people to buy a traditional manual Cayman now the PDK is available. The split is expected to be 50-50 between the two transmissions, whereas the old automatic transmission only accounted for roughly a quarter of Cayman sales.
The engines and PDK transmission are the headline acts for the new Cayman, which has also received a very minor exterior facelift.
The visual differences between the new and old model are strictly for trainspotters, with new headlight and bumper designs at the front and new tail lights and bumper at the rear.
The Porsche also has optional daytime running lights for the first time and high-intensity LED tail lights.
There are also optional bi-xenon headlights that can bend the beam to follow the curve of the road, while the wheels on both models have been redesigned.
Inside, the touch screen is bigger with fewer buttons and there are new optional Bluetooth and MP3/USB auxiliary packs.
The MP3 and USB options are connected to the entertainment system, which means the driver can scroll through their menus on the car’s touch-screen monitor.
The car’s wheelbase (distance between the front and rear wheels) and track (the distance between left and right wheels) are unchanged on the new car, but Porsche has tweaked the suspension and fitted bigger brakes to cater for the improved performance.
The ride is now more compliant thanks to new springs and dampers, as well as new compound tyres.
The steering has been retuned for easier city manoeuvring and the brakes now have a pre-loading function which moves the callipers closer to the discs in preparation for an emergency stop if the driver lifts off the accelerator pedal in a hurry. There is also a new hill-hold function.
As with all Porsches, the new Cayman comes with a long list of new options, starting with the PDK transmission, which is expected to add about $7000 to the circa-$150,000 base model asking price.
There is also a sports-chrono-plus package that adjusts the shift patterns of the PDK transmission for more aggressive, sporty driving at the press of a button.
A mechanical rear axle differential is available on cars with 18-inch and 19-inch wheels, improving traction out of corners.
The new Cayman will go on sale in March next year and pricing will be released closer to the launch.
source:stuff
