Broadly speaking, automakers consider hybrid drivetrains a mere stepping stone on the path to battery-electric vehicles. Paris-based Renault took a completely different approach: In 2012 it introduced the Zoe, an affordable electric car with about 150 miles of range, and it’s barely getting around to bringing its first-ever hybrid model to the market.
The new, fourth-generation Scenic people-mover is available with a mild hybrid drivetrain called, accurately enough, Hybrid Assist. Digital Trends trekked to the south of France to find out why the company finally decided to go hybrid — and what it means for the future.
How does it work?
On paper, Hybrid Assist is a relatively simple system. It’s built around a 1.5-liter turbodiesel four-cylinder engine (called dCi in marketing-speak) that makes 110 horsepower at 4,000 rpm and a generous 191 pound-feet of torque at just 1,750 rpm. The dCi is a popular, time-tested unit that has powered dozens of Renault, Dacia, Nissan, and even Mercedes-Benz cars over the past few years. In this application it’s bolted to a smooth-shifting six-speed manual transmission.
The hybrid part comes from a 48-volt battery neatly tucked under the trunk floor, a 10-kilowatt electric motor lodged in the engine bay, a generator, and a converter module that turns 48-volt current into 12-volt current. All told, the system weighs 108 pounds.
The decision to hybridize a turbodiesel engine and not a gasoline-burning unit might seem odd, but the company explains that the potential to boost fuel economy is much greater with an oil-burner. That said, Renault didn’t exactly jump head-first into the hybrid segment.
“We’ve already got an affordable, purpose-designed EV; a lot of our competitors haven’t even gotten to that point yet. Now we’re circling back and exploring other forms of electrification. We’re starting with a mild hybrid, but we’re toying with the idea of introducing a plug-in system further down the road,” affirmed a spokesman for the company.
A mild hybrid system represents a baby step, but at least it’s in the right direction. The Scenic is anywhere between eight and 10 percent more efficient when it’s equipped with Hybrid Assist. That means it returns 67 mpg in a mixed European cycle, and it emits just 92 grams of CO2 per kilometer. These figures are on par with the smallest, thriftiest economy cars sold on the Old Continent.
How does it drive?
The Scenic with Hybrid Assist sounds just like a standard Scenic when the oil-burner rumbles to life. The battery isn’t big enough to spin the wheels on its own, so don’t expect the car to whisk you and your passengers away in complete silence; this isn’t a Prius.
The Scenic is anywhere between eight and 10 percent more efficient when it’s equipped with Hybrid Assist.
The electric motors’ boost isn’t immediately perceptible, it doesn’t grab you by the seat of the pants and pin you against the seat, but it virtually eliminates turbo lag by providing 51 additional pound-feet of torque at 1,000 rpm. The effect is appreciable around town, especially as you enter a roundabout in second gear or pull away from a stoplight. When zapped with a few additional kilowatts, the dCi feels like a large, naturally-aspirated engine instead of a low-displacement, turbocharged mill. As a bonus, the system is light enough not to have an adverse effect on overall performance.
The Scenic can’t be plugged in, meaning the 48-volt battery exclusively stores electricity that’s produced by the generator when the engine is coasting. Topping it up doesn’t require a lot of juice, so the regeneration doesn’t stop the car dead in its tracks like it does in many hybrids and pure EVs. A few minutes behind the wheel is all it takes to figure out how to get the most electricity out of every stop.
A boost gauge added to the digital instrument cluster informs the driver whether the dCi is receiving electricity, generating it, or operating on its own. Unfortunately, there’s no way to tell how much charge is left in the battery. And, Hybrid Assist essentially shuts off as soon as the turbo spools up, so it’s on standby when cruising on the highway in sixth gear.
Renault explained it entered the hybrid segment because car shoppers and fleet operators are increasingly looking for efficiency, and because most of its main rivals already dabble in the technology. And while it hasn’t officially announced plans to expand its offering of hybrid cars, it’s difficult to imagine the company just went through the costly and time-consuming process of designing a diesel-electric drivetrain only to use it on a single model.
The gradual adoption of hybrid technology is the next step in the French automaker’s shift towards electrification.
A company spokesman told us that the hybrid drivetrain is highly modular, and it can be installed in a handful of cars including the Mégane (a Volkswagen Golf-sized hatchback) and the Talisman (a large sedan that competes in the same segment as the Passat).
“It’s not a simple bolt-on operation, engineers need to make room for the converter and the 48-volt battery, but it’s completely doable,” he added.
We wouldn’t be surprised to see both of the aforementioned models receive Hybrid Assist before the end of their respective life cycle. The seven-seater Espace is a likely candidate, too, especially because packaging would be relatively straight-forward due to its generous dimensions. Smaller cars like the Twingo and the Clio are less likely to receive Hybrid Assist, at least in the near future.
Renault pledges to continue developing electric vehicles. The company is one of the world’s EV leaders, and it’s not about to give up that position. However, it’s clear that the gradual adoption of hybrid technology is the next step in the French automaker’s shift towards electrification.