A question that we get asked quite often by some of readers is why after a few weeks of taking delivery, does their car consume more fuel than claimed by the manufacturer? The reason for that is because most of the consumption test data is gathered in a controlled environment. The revised WLTP system does involve some on-road testing which brings it closer to reality than the old NEDC method but still, tested figures remain rather generous.
It today’s test, we’re going to put four cars with different fueling systems on a lengthy drive through the Cape Peninsula to see which drivetrain can deliver a consumption equal to, better or worse than what the manufacturer has claimed. The four units that we’ll be testing today is an all-electric, petrol-hybrid, diesel and petrol sedan.
The first of our contender uses a more commonly accepted form of internal combustion as seen on South African roads. It’s the BMW 330i Steptronic which employs the brand’s 2,0-litre turbocharged four-cylinder engine to deliver 190 kW and 400 N.m of torque to the rear wheels via an eight-speed torque converter. As per CAR’s fuel index, this car consumes an average of 7,7 L/100 km with a CO2 figure of 147 g/km. With this, BMW says it’ll cover a range of 1 017 km before needing to be refueled.
Making use of a naturally aspirated 2,5-litre four-cylinder engine with an electric motor is the hybrid Lexus IS300h EX. With this powertrain, 164 kW and 221 N.m of torque is sent to the rears by means of a CVT which gives it a CAR fuel index consumption of 6,2 L/100 km and a CO2 figure of 122 g/km. From a full tank, Lexus says its IS300h can carry you for 1 534 before needing to be filled up again.
Bearing the oil-burning flag is the facelifted Audi A5 40 TDI Coupe S-Line Quattro S-Tronic which uses VAG’s 2,0-litre four-cylinder turbodiesel sending power to all four wheels via a seven-speed dual-clutch transmission. Using this, it bears a CAR fuel index of 7,4 L/100 km and a CO2 emission figure of 158 g/km. The turbodiesel coupe claims to carry a tank range of 769 km.
Representing the new preset of motoring is the all-electric Porsche Taycan which uses a two-speed motor mounted to the rear axle to produce a nominal power output of 280 kW and 357 N.m of torque. Fully charged, Porsche says its entry-level EV can travel for 395 km before needing to be plugged in again.