Australian Start Stop first for Subaru

Mon, 24/10/2011


Subaru is introducing Auto Start Stop technology in every new generation Impreza and XV – the first time a mainstream Australian small car range and Compact Sports Utility Vehicle range have featured the fuel-saving technology.   

Every Symmetrical All-Wheel Drive Impreza and XV variant will debut next year with Auto Stop Start, which also helps to reduce emissions.

It is one of several factors contributing to the outstanding fuel efficiency of both new models – Impreza emissions are improved by up to 24 per cent in the combined cycle while fuel efficiency is improved by up to 22 per cent in the combined cycle.

Engine Combined (l/100 km)/CO2 (g/km) Urban Extra urban
XV 2.0i six-speed manual 7.3/168 9.2/212 6.2/143
XV 2.0i Lineartronic™ 7.0/162 8.9/205 5.9/137
Impreza 2.0i six-speed manual 7.1/164 (MY11*: 8.9/210) 9.2/213 5.9/137
Impreza 2.0i Lineartronic™ CVT 6.8/157 (MY11: 8.8/208) 8.9/205 5.6/130

(*MY11 Impreza available with five-speed manual and four-speed auto-only).

Nick Senior, Managing Director, Subaru Australia, said: “All-Wheel Drive equals both safety and efficiency in our new generation Subarus.

“We were the first mainstream brand with five-star safety across the range and now we’re the first with ultra-efficient stop start technology across entire mainstream small car and compact SUV ranges.

“Subaru is able to achieve such outstanding fuel consumption because the Boxer engine and symmetrical drivetrain are easily compatible with lightweight All-Wheel Drive.”   

Mr Senior said Subaru’s renewed focus on fuel efficiency was also highlighted in a recent Liberty 2.5i economy run from the Melbourne Cricket Ground to the Sydney Cricket Ground.

Respected motorsport driver and Subaru ambassador Dean Herridge drove against former NRMA engineer and economy driving expert Bob Hudson to see who could achieve the lowest fuel consumption in normal driving conditions.

Both produced figures far below the official combined fuel consumption for Liberty 2.5i.

Model and driver Total drive time Progressive total distance Average driving speed Average fuel consumption (calculated on distance travelled and fuel inserted) Official combined fuel consumption
Liberty 2.5i Lineartronic™ CVT sedan. Driver: Dean Herridge 9 hours, 34 minutes 895.2 kilometres 93.5 km/h 6.63 litres/100 km 8.3l/100 km
Liberty 2.5i Lineartronic™ CVT wagon. Driver: Bob Hudson 10 hours, 24 minutes 901.5 kilometres 86.7 km/h 6.24 litres/100 km 8.3l/100 km

** Please see video on accompanying USB.

Mr Senior added: “The fuel efficiency of new Impreza and XV, plus the results achieved by Dean and Bob in current Liberty, debunk the myth that AWD cars are less efficient.

“Not only are they highly competitive, they have the added safety benefit of AWD, for great handling, grip and fun.”

Auto Start Stop background

Auto Start Stop stops the engine when the vehicle is temporarily stationary, such as at traffic lights. It reduces fuel consumption.

In Lineartronic™ CVT-equipped vehicles the engine stops 0.5 seconds after the car halts. When the brake is released, the engine starts after 0.35 seconds.

In six-speed manual Impreza and XV, the engines also stops 0.5 seconds after the car halts, when the car is in neutral, or the clutch released. It restarts 0.35 seconds after the clutch is pressed.

FHI studies indicate cars may be stopped up to 30 per cent of travel time, particularly in peak hour.

An “off” button enables Auto Start Stop to be turned off – the default is “on”.

A special starter and Inrush Current Reduction (ICR) relay are among the components supporting Auto Start Stop. The ICR relay stabilizes power supply during idle reduction, so instruments and displays do not flicker.

The starter in Lineatronic™ CVT Impreza and XV features tandem solenoids. Independent solenoids control the motor and the pinion gear connecting engine and motor rotation, ensuring rapid engine restart in as little as 0.2 seconds. An electric pump supplies oil to the forward clutch’s hydraulic circuit while the engine is stopped. This minimizes delay between engine restart and vehicle motion, producing smoother driving.

During Auto Start Stop operation, the air conditioner, navigation and audio systems are all fed by the auxiliary power supply.

Vehicles with Auto Start Stop are fitted with a long-life battery.

On XV manual variants, Hill Start Assist  ensures Auto Start Stop operates safely on hills.

To avoid wasting electrical energy, the car’s electric power steering is turned off whenever the engine is automatically stopped.



Every Subaru sold in Australia features Symmetrical All-Wheel Drive and a horizontally opposed Boxer engine, standard Vehicle Dynamics Control electronic stability program, and a five-star rating for occupant safety from the independent Australasian New Car Assessment Program (ANCAP). The result - driving confidence.



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