Jaguar tests XF ‘Flybrid’

JAGUAR has revealed it is testing a flywheel hybrid system that could reduce fuel consumption by up to 20 per cent while increasing power output by as much as 60kW.

Presented in an XF sedan prototype at the Low Carbon Vehicle event near Millbrook last week, the so-called Flywheel Hybrid System for Premium Vehicles (FHSPV) is a £3 million ($A4.95m) project funded to the tune of around £2.2 million ($A3.63m) by the British government’s Technology Strategy Board.

The British-engineered hybrid system, packaged into the rear axle of an XF test prototype, is being evaluated as an alternative to battery hybrids for storing waste energy during braking, and comprises components from UK engineering specialist Flybrid Systems, as well as Torotrak, Xtrac and Prodrive, plus input from Ricardo.



Left: Xtrac technical director Adrian Moore (left), Torotrak CEO Dick Elsy and Flybrid managing partner Jon Hilton.

Currently being tested in stop-start city traffic to maximise the generation of lost braking energy as ‘free’ power, the composite flywheel is driven through a Torotrak/Xtrac CVT gearbox and spins at up to 60,000rpm to store peak power of 60kW, which can be delivered at any engine speed, but only for up to seven seconds at a time.

Combined with a stop-start system, Jaguar says it is targeting CO2 reductions of up to 20 per cent with the system, which weighs 65kg – about half the weight of a comparable hybrid drive system, according to Jaguar.

Jaguar claims that, as well as being more compact and cheaper to produce than similarly effective hybrid systems, the FHSPV unit can also be adapted for use in a range of vehicle types, including SUVs from sister brand Land Rover.

In the XF, however, Autocar reports Jaguar engineers had to cut away a quarter of the spare wheel well and fabricate a modified rear cross-member to accommodate it.

In fact, the production future of the FHSPV system remains unknown as the cost of battery hybrids continues to reduce and fuel consumption reductions continue to be made by most car-makers.

“Hybrid engineering is the most exciting, challenging job for any science graduate in the car industry today,” said Jaguar Land Rover’s hybrid group manager Mike Richardson at the British Science Festival in Birmingham, also held last week.

“It is ironic that electric vehicles have actually been around for more 100 years, but the course of history took the early automotive pioneers down the route of today’s petroleum-based internal combustion engine. This means that we are now playing catch-up with regards to the mass commercialisation of electric propulsion technologies and infrastructure.

“For premium vehicles, plug-in hybrids present the next and most immediate potential and there is broad acceptance across the industry of a technology roadmap that sees electric vehicles as the ultimate solution to the low carbon vehicle challenge.

“Our plan and expectation at Jaguar Land Rover is that these will evolve through hybrids, plug-in hybrids and range-extended hybrids. “This joint understanding frees up the opportunity for some innovative consortia and collaborative effort, as well as providing a platform for funding and investment.” Jaguar has more than 100 engineers working specifically on hybrid technology and is currently recruiting to increase that number.

Apart from the FHSPV system, Jaguar is working on another research project, also funded by the British government’s TSB, dubbed Lime Green and based on the XJ limousine. A ‘series hybrid’ with an all-new range-extender powertrain, Jaguar says Lime Green will produce CO2 emissions of less than 120g/km while also offering a 180km/h top speed, an 800km driving range and zero-emissions capability for 50km.

Another project – the Range Extended Hybrid Electric Vehicle (REHEV) – is based on a Range Rover Sport and aimed to research a plug-in diesel electric parallel hybrid system suitable for a range of applications. The REHEV system allows the Rangie Sport to run in EV mode for 30km and provides assistance on the move while returning as little as 94g/km.

Land Rover has also committed to testing its first diesel hybrid prototype, also based on the Rangie Sport, by the end of this year. As part of the Technology Strategy Board Ultra Low Carbon Fleet Trial, the ‘Range_e’ will use the existing 3.0-litre TDV6 diesel engine in conjunction with an eight-speed ZF automatic transmission.

Its goals are to achieve a range of 32km using electric power only, CO2 emissions of less than 100g/km and a top speed of around 195km/h.