Nissan has finally electrified its Juke – from the end of July, a hybrid version of the successful small SUV will be on UK roads. “So it will be just like any hybrid?” one of our fellow motoring writers asked at the launch, and the answer is not at all…
The petrol-electric powertrain fitted in the Nissan Juke is quite different to those you might find in other models such as the standard-bearer of hybrid driving, the Toyota Prius. Instead the Nissan uses technology first seen in sister brand Renault’s Captur and dubbed E-Tech, which both brands insist is rather more efficient.
Either, or both…
Hybrids are normally one of two types. In a parallel hybrid (which is most hybrid vehicles on UK roads), both the electric motor and the engine can drive the wheels, usually working together. In a series hybrid, the wheels only receive their propulsion from the electric motor, with the petrol engine merely being there to generate the electricity to power the motor. The Nissan Juke unit, however, can work in series, parallel or both…
We are told the system was developed using technology developed by Renault’s Formula One team and for the first time is based around an internal combustion engine specifically developed with hybrid in mind. It’s a more compact version of a Nissan 1.6-litre unit, combined with a 36kW electric motor also made by Nissan, while Renault’s contribution is the 15kW high voltage starter/generator, the inverter and the 1.2kWh water-cooled battery, which is housed under the boot floor.
All this adds up to rather more potency – 25% up on a typical petrol-powered Juke. We don’t have confirmed fuel economy figures yet, but Nissan reckons that the Juke should return combined fuel consumption improved by up to 20% – 40% if running around town.
Two motors better than one
Where the Juke gets particularly clever compared to a typical hybrid is that it has a second, smaller, electric motor in its gearbox, another Renault item. This gearbox has no conventional synchroniser rings, but dog clutches instead, and no proper clutch as in a conventional car. But these are the elements that enable rather more efficiency.
There are four ‘internal combustion’ (ICE) gears and two ‘electric vehicle’ (EV) gears, and the latter are powered by that second electric motor, sending their propulsion through a different path to the wheels than do the ICE gears – the Juke always starts using electric power only, and the EV gears are used to synchronise the ICE ones.
Clever electronics – the bit supposedly descended from Formula One – control the shift points, regeneration of the battery and which format of hybrid power will deliver the best efficiency for what the driver is demanding through their right foot. And the input between motor, engine or both is so seamless that the driver simply doesn’t notice the changes.
Confused yet? Well you don’t need to understand the tech, just appreciate what it produces. According to Colin Goldsmith, from the Nissan UK technical department, being behind the wheel of the Juke is much closer to driving an electric car than are more typical hybrids. “It’s a much more connected feel. With a standard hybrid you feel like you are driving an ICE car with the hybrid coming in short bursts, with the Juke you get that EV feel all the way through.”
Goldsmith adds that the car always starts in electric mode; “There is then a transition when the system determines that the ICE engine should join in, to give you more power or more drive, while it will also determine if the battery charge is dropping and direct some charge to the battery.
“All this is done by the system and you won’t feel the cutting-in of the engine like you do with a normal hybrid. Effectively it feels like you are driving a normal automatic car – you put your foot down and it drives.”
Extended electric
A key part of designing the Juke Hybrid was maximising the time the car spends in EV mode, and the designers claim to have achieved up to 80% of an around-town drive powered by electricity. Your mileage may vary, but the company is confident that this new hybrid system will provide far more electric (and far less petrol) usage in urban driving.
It can reach speeds up to 34mph in EV mode, and you can push a button to only drive on electric, though you won’t go very far, a mile or two, before the engine needs to cut in and replenish the battery. “You can force the EV mode, perhaps to drive through a city centre or a multi-storey car park, but it won’t go so far as to drain the battery,” Goldsmith says.
Also helping to keep the battery topped up is an ‘e-pedal’, previously seen on the fully-electric Nissan Leaf hatchback. While, like most EVs, when the car slows the electric motor acts as a generator and returns some charge to the battery, using the e-pedal maximises this effect. As soon as one lifts off the accelerator moderate braking is applied, and given enough space the car will slow to a halt – it is very easy to drive the Juke as a one-pedal car, hardly ever needing to use the brake pedal.
The figures? Combined the hybrid power unit produces 143hp, compared to 114 for the petrol-powered Juke. This means it completes a 0-62mph sprint in 10.1 seconds, 1.7 seconds faster than the ICE Juke.
Yet while the latter with an auto transmission returns fuel economy of around 45mpg and produces CO2 emissions of around 137g/km, Nissan expects fuel economy of more than 55mpg and emissions down to around 114g/km from the hybrid. We’re still awaiting the official figures but it’s clear the petrol-electric Juke is the greener and more economic option.
“The engine has been optimised to the hybrid system,” Goldsmith says, “developed to have a lower fuel consumption, with lighter weight because the hybrid is more compact. You’ll see much better performance and fuel consumption compared to a normal ICE engine, and compared to a conventional hybrid you will see improvements but the level will depend on driving conditions and style.”
So does Goldsmith see this as the future of hybrid? “It’s one – there are a range of ways of electrifying cars and we have the Nissan e-Power system in the Qashqai as well as the excellent electric system in the Leaf. But the new hybrid is a very good solution and a definite step forward.”
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