South Africa’s first pair of plug-in electric SUVs simultaneously debut on the market. We choose a winner…
Large SUVs were once the archenemy of tree-huggers everywhere. Spewing forth more CO2 than was prudent, these vehicles and their owners were ostracised by anyone with an eco-conscience. However, the proliferation of hybrid technology has given even traditionally large, gas-guzzling SUVs a new lease on life.
The cars you see here, however, aren’t just any hybrids; these are the very first plug-in hybrid-electric-vehicle (PHEV) SUVs available in South Africa. Fortuitously, BMW and Volvo chose the same time to debut the newest members of their respective SUV ranges and we managed to grab both models to bring you this comparison.
Future watch
What a decade ago may have seemed like science fiction is now a reality. You glide silently into your garage, park your vehicle, connect it to the wall socket to “fill up” and step inside to greet your family. As odd as it may sound to generations of drivers brought up on a steady diet of internal-combustion engines, this is exactly what these two SUVs offer.
Different approaches
Outside of BMW’s “born electric” i3 and i8 offerings, the X5 xDrive40e is the German automaker’s first PHEV. Using lessons gleaned from those i models, Munich’s engineers have come up with a very simple solution for the 40e’s powertrain. Integrated in the transmission is a synchronous electric motor that provides maximum power of 83 kW at 3 170 r/min and 250 N.m of torque. The internal-combustion engine (ICE) component of the powertrain is similar to that found in a 330i and the 2,0-litre turbopetrol produces 180 kW and 350 N.m. As the electric-drive unit sends power through the gearbox, both electricity and petrol are used to power all four wheels, with a total system power rated at 230 kW and 450 N.m.
Volvo’s engineers have opted for a slightly more complex drive-train solution. A crank-mounted synchronous generator provides up to 34 kW of power and 150 N.m of torque. This unit can charge the battery and acts as a starter for the ICE, too. However, the Electric Rear Axle Drive (ERAD) provides the bulk of the electrical drive. This generates 65 kW and 240 N.m, and is solely responsible for propulsion in electric-only mode. This unit is also what gives the T8 all-wheel-drive functionality, as there is no mechanical link between the front-mounted powerplant and rear wheels. Ironically, this layout is very similar to that employed in BMW’s i8. The XC90’s ICE is the same super- and turbocharged engine as found in a T6 derivative, which provides 235 kW and 400 N.m. The total system power is rated at 300 kW, with 640 N.m of torque.
Plugging in
As the description denotes, plug-in hybrids are able to connect to traditional electrical outlets to recharge their batteries. This is in contrast to the hybrids with which most people are familiar that utilise an ICE to charge up a battery. The hybrid part of the PHEV equation ensures that owners will never get caught flat-footed, as petrol-fed engines conveniently ensure there’s no limit to how far you can drive your “electric” SUV.
Both models offer the convenience of plugging into domestic wall-sockets to recharge their batteries. In the case of the X5, this process can take as little as two hours and 45 minutes if you have the optional i Wallbox Pro installed, and just fewer than four hours via mains. In comparison, the T8 takes a shade under three hours from a plug point. If the current from the outlet is as high as 16 A, the time is reduced by about 30 minutes.
To provide electrical current, both cars utilise lithium-ion battery packs consisting of 96 cells each. In the BMW, the battery is housed beneath the boot board, resulting in a fractional reduction of boot space. However, Volvo’s architecture means its battery pack is more ergonomically tucked away in the transmission tunnel. Except for a small drop in fuel-tank size, by doing so the T8 maintains the full level of practicality of other XC90 models and retains its seven seats. That’s a definite plus for the Volvo. It’s worth noting, though, that neither vehicle carries a spare wheel.
Charged up
With a 9,0 kWh battery, the BMW costs R13,86 to “fill up”, while the Volvo’s 9,2 kWh unit is negligibly higher at R14,17. A fully charged battery provides a claimed range of 31 km in the X5, provided you drive in a gentle manner. Top speed in this mode is limited to 120 km/h. The T8 has the edge in this department, with a range of 43 km, almost 50% further. Another big point for the Volvo.
Incidentally, our test team all live within the claimed range of the Volvo’s battery from the office and most managed to make it all the way home without once using a drop of fuel. In the cost-per-kilometre calculations, assuming you can commute purely on electrical power, the XC90 is the clear winner, with a low 33 c/km versus 45 c/km for the X5. That said, if you can manage your daily commute inside the pure electric range, both figures are impressive.
While both cars feature an electric-only driving mode, they also afford drivers the opportunity to commute solely on petrol power. Driving in this mode allows you to charge the battery and save electric power to use at a later stage. For example, if you were to enter a city that levies congestion tax or an urban area where you’d prefer to travel silently, you have the SUVs’ full zero-tailpipe-emissions capabilities at your disposal. We did note that, during testing, the BMW managed to complete this charging task more effectively than the Volvo.
As the New European Drive Cycle (NEDC) strongly favours urban driving, both SUVs boast claimed consumption figures that are scarcely believable. Even after multiplication by our fuel index (we add 20% to carmakers’ figures), the X5’s 3,96 and XC90’s 2,5 L/100 km appear wildly optimistic. Our standardised, mixed-environment fuel route returned figures that are more representative of the real world: 8,3 L/100 km for the BMW and 6,6 for the Volvo. A convincing win for the Swede in another area that is crucial for a hybrid.
On the move
It’s a great party trick, the way electric cars power up with no engine noise. Silently moving off, each car displays excellent NVH characteristics. When more power is demanded from the driver, the respective ICEs seamlessly supplement electric motivation. Each car transmits power via an eight-speed automatic transmission. In both cases, they swap cogs with near imperceptibility; short of the movement of the rev-counter needle, you’d be hard pressed to spot the shifts.
There is a multitude of driving modes available to pilots of either vehicle. While each features different names, they essentially offer the same options. You can choose between electric-only driving (until battery charge is depleted); solely petrol driving to save battery power; and a default mode, which provides a seamless combination of the two. In the XC90, there is also an off-road mode that engages an electronic differential-lock function which provides power to each wheel to ensure surefooted progress off-road.
The 40e seems to ride along with a level of waftiness we’ve not experienced before in an X5. The improved ride could well be a function of the air springs employed on the rear axle. Even the control weights feel decreased by a notch or two, which makes it feel more rounded as an SUV rather than trying to be a sportscar. It’s a close call in this department, as the XC90 also rides well, but it should flaunt exemplary ride characteristics when you realise that it rolls on noticeably larger tyre sidewalls. This round goes to the BMW, but only just.
Not that performance should matter much when considering a PHEV SUV, but both cars impressed during testing. Despite weighing more than two tonnes each, they zip off the line. The XC90 dashed to 100 km/h from standstill in just 5,66 seconds, which will see off just about any hot hatch this side of a Volkswagen Golf R. The X5 was quite a bit slower, recording a best time of 6,99 seconds. The BMW managed to regain some credibility during the in-gear test procedures, with times just fractionally slower than those posted by the T8.
Even during braking, these SUVs impressed, with both earning excellent ratings in our 10-stop regimen. As with most hybrids/EVs, the brake-regeneration systems in these PHEVs require a slight recalibration of your driving style. Lifting off the throttle causes a sharp decrease in speed as kinetic energy is converted into electrical charge.
