HOLDEN VOLT REVIEW
What’s Hot: A new standard for everyday, ultra-efficient motoring
What’s Not: $59,990 price of entry still beyond mainstream buyers
X-Factor: The pinnacle of on-road EV technology, delivered in near silence
Vehicle type: Extended-range EV small hatch
Fuel Use (tested): 2.6l/100km
Holden’s Volt range-extended EV is impressive on some fundamental levels.
Sure its energy efficiency and underlying technologies put it at the forefront of modern automotive engineering design, but, at its most basic, it perhaps impresses most for the way it operates as “a car”- in doing all the things we expect of a vehicle.
On our experience to date, we’re convinced the Volt’s unique (for now) petrol-assisted electric drivetrain is a significant step forward as a technological solution to ‘everyday’ fuel-efficient motoring.
But what we’re increasingly discovering is how ably it delivers the relaxed drive experience of conventionally-fuelled vehicles.
Due for sale in November, TMR was on hand for the latest phase of Volt’s Australian launch - a briefing by key GM Holden engineers on what lies beneath the Volt’s skin, and how it embodies the road ahead for future GM models.
Paul Gibson, Holden’s director of Electronic Engineering was on hand to explain the Volt’s innovative drivetrain in detail.
The Volt’s ability to rely almost exclusively on electric power is now common knowledge, thanks to its 87km official pure-electric range, and ability to be completely recharged from a standard power outlet in under ten hours - all for about $2.50.
For trips greater than 87km, the Volt packs a 1.4 litre petrol engine as a backup plan, with a 36 litre fuel tank to add over 500km to its overall range.
Similarly, the Volt’s ‘Voltec’ drivetrain has been well documented, with its main 111kW/370Nm ‘traction’ electric motor, smaller 55kW ‘generator’ motor and 63kW 1.4 litre petrol motor, all integrated using clutches and a continuously variable planetary gear-set (in lieu of a traditional transmission).
Holden’s local Volt development has been largely centred around ensuring compliance with Australian 240V mains power (compared with 120V in Volt’s native US) - the Volt can be recharged at any standard Australian powerpoint with its on-board power cord.
Where possible, a 10 Amp charge can be selected via the simple dashboard menu, bringing the complete charge time to under six hours.
Holden is able to provide advice as to which home powerpoints are capable of a 10 Amp charge, while a sub-four hour complete charge is possible at dedicated charge points like those provided by Better Place.
While charging, the Volt’s charge status is signified by a charge light located at the base of the windscreen, indicating full charge with a solid green light - just like most mobile phones or power tools.
When underway, the main traction electric motor is used for acceleration from rest and slow speed manoeuvring, while the generator motor is phased in at higher cruising speeds to make optimal use of the available charge.
The Volt’s ability to avoid petrol use altogether has inspired competition among a number of US owners. TV host Jay Leno famously claims to have travelled nearly 18,000km on less than half a tank of petrol.
To prevent such unused petrol going stale, the Volt’s 36 litre fuel tank is pressurised in a similar process used in food packaging.
Similarly, the petrol engine will automatically cycle every 48 days to ensure adequate lubrication for drivetrain longevity.
If the petrol engine is called upon to supplement a depleted battery system, it will drive the generator motor, which will in turn provide electricity for the traction motor, which then provides power to the wheels.
This chain of command may seem convoluted, but GM has found that this configuration is more efficient than if the petrol motor were connected directly to the wheels.
Although supplementing the battery charge when driving, the petrol engine will not provide charge to the Volt’s battery when depleted.
Only mains charging and regenerative braking will directly recharge the battery system, in the interest of absolutely minimising petrol consumption.
Maximising the Volt’s battery efficiency is a liquid cooling system, which circulates liquid around the cells to maintain an ideal 0-35 degrees Celsius operating temperature.
Holden’s factory warranty covers the battery system for 6 years/160,000km; GM testing suggests a battery life expectancy of 15-20 years.
Aside from scoring a top 5-Star ANCAP rating, the Volt brings lane departure warning, and forward collision alert technologies to the Holden range for the first time.
Holden flew in Kristen Siemen, Executive Director of GM’s Electrical Systems division for the event, who explained that these features are part of GM’s quest toward autonomous vehicles, ones that remove the human element - and human error - from ensuring passenger safety.
To date, systems like GPS and stability control have largely worked independently of one another, but GM believes they can work hand-in-glove for the sake of safety.
Termed ‘sensor fusion’, GM is working toward integrating these systems’ radars, cameras and ultrasonic sensors to better advise drivers of danger and ultimately intervene to prevent collisions.
Such fusion is already evident in some luxury models, but Ms Siemen believes the technology will be seen across all segments within a decade.
The Holden Volt’s infotainment system is yet another area which sets a new standard for the local carmaker.
Ranging from the innovative touch sensitive centre stack, to twin seven-inch displays and an impressive suite of connectivity, navigation, media storage and playback options, the Volt’s system reflects a rising demand for such features in modern vehicles.
GM’s Chevrolet MyLink system is designed to provide convenient interaction with a driver’s smartphone and related internet capabilities.
MyLink is already available on some US models, and is aimed at balancing modern connectivity needs with occupant safety, keeping ‘eyes on the road, and hands on the wheel’.
GM acknowledge that some drivers will continue to use their handsets whilst driving, but aims to combat this by making vehicle integration as seamless as possible.
Key areas identified to enable this are simplicity of the user-interface, compatibility across handset models, and expanded voice activation capabilities.
Holden would not confirm so, but we expect a similar system to debut locally in the VF Commodore next year.
At the end of the day, we were tossed the keys to a Volt which had roughly half its battery charge remaining, suggesting we’d have the chance to experience the Volt in pure electric, and petrol-assisted modes.
Under pure-electric drive, the Volt delivers overall refinement levels well in excess of its $59,990 pricetag, highlighting how fundamentally unrefined an internal combustion driveline is.
Aside from the occasional faint whir from the driveline, the Volt wafts along in near silence. Try driving your normal car with earplugs, you’ll see what we mean.
Once the batteries charge was depleted, a momentary beep signified the intervention of the petrol engine. This could also be felt through the characteristic engine throb, but this transition made no noticeable difference to the Volt’s performance.
As suggested in Paul Gibson’s technical overview, the petrol engine’s revs flared according to the electric motors’ demands for charge, not according to the accelerator - remember, the petrol motor is not connected directly to the driveline.
This can be quite uncanny, as the petrol engine’s revs can flare up to four seconds after the throttle is stabbed, and can rise without provocation at all while cruising.
Observing the Volt’s multi-faceted driveline at work is quite marvellous, and the driver is left with the impression that the car is genuinely smarter than they.
For the record, our Volt travelled 59.9 kilometres on the day purely on the battery’s charge, falling nearly 30km short of the Volt’s official range of 87 kilometres.
In fairness, much of this charge was spent cycling through media personnel under ‘see what it'll do’ conditions and stop-start city traffic.
After 102.4 kilometres of this same city driving, our Volt displayed an average fuel consumption readout of 2.6 l/100km, remarkable for a 1700kg vehicle, regardless of the trying driving conditions.
The Volt may miss out on the ultimate ‘zero emission’ boast of the Nissan Leaf and Mitsubishi iMiEV, but it can avoid emissions (and petrol use) on most commutes, with the trump card of a further 500km+ petrol-assisted range when needed.
Holden Volt - $59,990 (plus on-roads)
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