Generally speaking, hybrid vehicles are engineered to be as frugal as possible whilst still retaining a healthy amount of passenger comfort, for they cater to eco-minded folks who still want comfortable motoring. After all, only extreme eco-warriors would go as far as boycotting motorised transport to save the planet. Even if these environmentalists rode a bicycle, it would probably be made from scrap metal that they salvaged themselves.
Anyway, back to the car here. Currently (at press time), all hybrid passenger vehicles sold in Singapore are of the petrol-electric variety, except two models: Mercedes-Benz’s E300 BlueTec Hybrid and the Peugeot 508 RXH here, both with diesel-electric powertrains. In theory, diesel-electric hybrids should be the way to go for eco-friendly driving, since a diesel engine is already more frugal than its petrol-fuelled equivalent.
The 508 RXH, which is also the top variant of the 508 range, is the product of that thinking, but design-wise, you wouldn’t imagine that there was anything “green” about this estate. In fact, it looks even more masculine than the diesel-powered 508 SW GT it replaces in Peugeot’s local lineup, thanks to a more assertive grille and “claw-like” daytime running lights on either side of the front bumper.
The 508 RXH is also 45mm taller than the 508 SW GT. Complementing this additional ground clearance are the plastic mouldings that envelop the bottom of the vehicle from front to rear. The 508 RXH is not an off-roader, but given its stance, it certainly aspires to be one.
In contrast to the car’s rugged exterior, the cabin is classy and refined. The seats are upholstered in a combination of Nappa leather and Alcantara, while the dashboard and centre console feature a glossy black trim. For an added touch of modernity, the cabin is even illuminated by LED lights.
Equally advanced, too, is the HYbrid4 powertrain, which uses a 2-litre turbo-diesel engine and an electric motor to drive the front and rear wheels, respectively. To enhance efficiency, Peugeot has employed a drive-by-wire setup – there’s no driveshaft linking the front and rear axles. The electric motor and nickel-metal hydride batteries are also neatly packaged below the rear of the vehicle, which means passenger space and boot capacity are not compromised.
The HYbrid4 system offers four driving modes: Auto, Sport, 4WD and ZEV. These are chosen using the selection knob beside the gearshift lever. As its name implies, the default Auto mode helps optimise fuel efficiency by minimising the use of the diesel powerplant and maximising the use of the electric motor. In Sport, both power units work simultaneously to deliver a more dynamic driving experience.
The 4WD setting is a bit of a misnomer, though, because it is not permanent. In this mode, the HYbrid4 system simply balances both motors in order to enhance traction over slippery surfaces. The ZEV (Zero Emission Vehicle) setting, on the other hand, will see the car running on electric power alone. It can do this at speeds of up to 64km/h, for up to four kilometres.
Another benefit that the electric motor provides is its ability to smoothen out the gearchanges of the 6-speed automated manual. Unlike non-hybrid Peugeots equipped with the same transmission, the 508 RXH doesn’t suffer from momentary power losses during gearchanges, because the electric motor fills those “gaps”.
However, while this estate is smooth at moderate to high speeds, it isn’t as polished at low speeds. The diesel engine shudders palpably whenever it starts and stops, which makes crawling through traffic jams all the more tiring. And when it repeats this behaviour during parking manoeuvres, you can’t help but wonder: Why doesn’t the electric motor just take over?
What’s even more bothersome is how, in its quest to reduce fuel consumption, the car keeps switching off the air-con compressor. This is fine in temperate climates, but in Singapore, cooling down the cabin seems to take hours instead of minutes. Mind you, Peugeot’s air-conditioning is normally quick and effective.
The 508 RXH also isn’t as frugal as expected. Although we knew achieving the claimed mileage of 25km per litre would be impossible, the 14km per litre we averaged over three days was below the 17km per litre we’d anticipated.
This diesel-electric estate is a quality product with genuine green credentials, but Peugeot has some more work to do before its potential as a French flagship can be realised fully.
SPECIFICATIONS
DRIVETRAIN
TYPE Inline-4, 16-valves, turbo-diesel hybrid
CAPACITY 1997cc
BORE X STROKE 85mm x 88mm
COMPRESSION RATIO 16:1
MAX POWER 200bhp at 3850rpm
MAX TORQUE 450Nm at 1750rpm
POWER TO WEIGHT 113bhp per tonne
GEARBOX 6-speed automated manual
DRIVEN WHEELS All
PERFORMANCE
0-100KM/H 9.5 seconds
TOP SPEED 213km/h
CONSUMPTION 25km/L (combined)
CO2 EMISSION 104g/km
SUSPENSION
FRONT MacPherson struts, coil springs
REAR Multi-link, coil springs
BRAKES
FRONT / REAR Ventilated discs / Discs
TYRES
TYPE Michelin Pilot Sport 3
SIZE 245/45 R18
SAFETY
AIRBAGS 6
TRACTION CONTROL ABS with ESP
MEASUREMENTS
LENGTH 4823mm
WIDTH 1864mm
HEIGHT 1521mm
WHEELBASE 2815mm
KERB WEIGHT 1770kg
TURNING CIRCLE 12.3m
BUYING IT
PRICE INCL. COE $234,404 (after $15k CEVS rebate)
WARRANTY 3 years/100,000km
WE SAY
+ Well-built interior, handsome styling, smooth and composed ride
– Inefficient air-con, rough powertrain at low speeds, less frugal than expected
