Kelly Taylor / Winnipeg Free Press
Owen Thunes, an engineer from Nissan’s Technical Center, says faster processor speeds in the computer driving the 2018 Nissan Leaf’s power inverter translates into more power and torque from the motor.
OTTAWA — It is, interestingly enough, an increase in computing power and not a change in the engine or batteries that’s behind a 37 per cent increase in horsepower for the 2018 Nissan Leaf.
Owen Thunes, an engineer from Nissan’s Technical Center near Sacramento, Calif., said faster processor speeds in the computer driving the power inverter — which converts the drive battery’s direct current into alternating current to power the motor — along with increased cooling ability, allow Nissan to develop higher voltages at the inverter’s output, which translates into more power and torque from the motor.
“The motor itself hasn’t changed, it’s all in the inverter,” Thunes said.
Look, a detailed explanation would require a discussion about such things as root mean square and P=I2R, but suffice it to say, Nissan is getting more power by being smarter, not less efficient.
Taken by itself, the Leaf’s 147 peak horsepower (up from 107 in the previous generation) isn’t all that impressive. But since it’s torque, not horsepower, that moves you, the car’s 236 pound-feet of torque should get your attention.
Thunes said the higher voltage created by the inverter generates more horsepower, while, at the same time, changes in battery construction and chemistry extend the Leaf’s range, now out to 242 kilometres. First, they changed the chemistry involved, from lithium-magnesium-oxide to nickel-metal-cobalt. Second, they changed the way layers in each cell of the battery pack are constructed, adding nine millimetres to the thickness of each cell. Yet by changing the pack from 48 modules of four cells (for a total of 192), the packs now contain 24 modules of eight cells, which allows for packing more power in the same space.
The other significant change for the 2018 Leaf is the addition of the e-pedal driving mode. This mode, which is selected separately by the driver, allows for one-pedal operation of the vehicle except in emergency stopping situations. E-pedal ramps up the amount of regenerative braking to the point that for most driving, simply lifting the accelerator is enough bring to the car to a halt.
Thunes said the goal is to provide a driving mode that reduces driver fatigue, while at the same time increasing the amount of power recovered during deceleration. For stop-and-go traffic, for driving twisty roads and for driving up or down hills, e-pedal mode lets the driver use only the accelerator pedal.
“Of course, if you need to stop suddenly, use the brake pedal just like you would normally do,” he said.
E-pedal turns off the “creep” mode, which in normal driving modes makes the car drive like any automatic transmission-equipped vehicle, where the car creeps forward when in “drive” and the brakes are not engaged. For stopping, the e-pedal mode uses aggressive regenerative braking to deliver up to 0.2 G of stopping power, while finishing off a stop by using the traditional brakes. For longer stops, it automatically engages the parking brake.
The benefits are two-fold: on hills, the car keeps itself from rolling, either backwards when on an up slope or forward on down slopes. When it’s time to go, you just push the accelerator and it takes off.
In “drive” and in “b” modes, the car operates like any other, with a programmed creep just like normal cars and the need to use the brake pedal. E-pedal is selected separately.
Driving in the e-pedal mode became very intuitive, very quickly. Using just the accelerator pedal to accelerate, decelerate and brake was a lot of fun, particularly on twisty roads. What was interesting was how little gap we needed to leave before taking our foot off the pedal to come safely to a stop behind the car in front.
When the car is slowing significantly due to e-pedal mode, it will activate the brake lights regardless of any application of the brake pedal.
The steering and handling of the Leaf is also quite “normal.” It has, for obvious reasons, electric power steering, but it doesn’t feel the least bit numb, and it responds crisply to steering input.
François Lefèvre, marketing manager for Leaf in Canada, said the exterior design was intended to tone down the overt electrified styling of the old Leaf in an attempt to appeal to buyers who don’t want to wear their green on their sleeves.
As well, it evokes a familial connection to Rogue and Qashqai and Maxima through the incorporation of Nissan’s floating roof, boomerang lights for the daytime running lights and tail lights, as well as the V-motion design of the car’s grille.
But what about winter? Doesn’t the cold hamper range? Well, yes and no. If you’re plugged in up to your departure time, you can program the car to precondition both the interior and the battery temperature while plugged in, meaning keeping the interior warm and maintaining the battery temperature have a reduced impact on range.
As for that range, it will get you to Brandon, but not to Regina, at least not without planning a stop for charging along the way. Charging times vary from 16 hours (at three kilowatts) to 71/2 hours (at six kilowatts) to 40 minutes on a fast-charging DC charger.
That charging, by the way, can now be done at Level 2 using the supplied portable charging cable and 240 volts. The cable automatically switches to Level 1 if you plug it into 120 volts using a supplied adapter. The Leaf supports Level 3 charging (to 80 per cent in 40 minutes) and also supports bi-directional power flow, meaning that once the required household hardware becomes available, you could use the Leaf to power your house.
The new Leaf, like its gasoline crossover sibling Rogue, features ProPILOT Assist, which Nissan takes great pains to point out is merely a driver-assist function and is not any kind of autopilot.
ProPILOT Assist uses a camera and a radar unit to operate like a smart cruise control — keeping pace with traffic — and to centre the car in the lane. Unlike some lane-departure systems, it doesn’t require nearing the lane markings to keep the car centred. “It’s not designed to stop you from leaving the lane, it’s designed to keep you in the centre of the lane,” Thunes said.
The system will manage all aspects of stop-and-go driving, slowing down and stopping when necessary and resuming speed when traffic picks up. But it will not let you ignore your responsibilities as a driver.
Torque sensors ensure you’re keeping your hands on the wheel, and if you aren’t, you’ll get a series of increasingly intrusive warnings — from a gentle reminder to a voice warning to a loud alarm to taps on the brakes — before the car finally gives up, activates its hazard flashers and brings your car slowly to a stop.
In the event of a potential collision, the vehicle will activate autonomous emergency braking to stop the car, hopefully in time to avoid a collision or, at the very least, lessen the severity of it.
If there’s one takeaway from our day driving the 2018 Leaf around the Gatineau, Que., area, it’s how remarkably “normal” a vehicle it is. Sure, the transmission shifter is a bit unusual, the e-pedal, if you choose to use it, takes a moment to get accustomed to and the charge time is, at its shortest, 40 minutes, but when driving it, you get “normal” torque and horsepower and a “normal” feel to the steering.
That it might be only $3 to fill doesn’t hurt.
Kelly Taylor / Winnipeg Free Press
Charging times vary from 16 hours (at three kilowatts) to 71/2 hours (at six kilowatts) to 40 minutes on a fast-charging DC charger.
Kelly Taylor / Winnipeg Free Press
Outside the Canadian Museum of Nature, Ottawa.