Volkswagen Think Blue Challenge

To describe Volkswagen Australia�??s past month as a challenge would be an understatement.

The opportunity to put its recall headaches to one side and showcase its environmental credentials with a challenge of a different kind came as a welcome breather for the German brand intent on turning around its recently sullied public image.

After addressing the elephant in the room in a 15-minute recall Q&A session, it was down to the business of the real reason a group of motoring journalists had been assembled in Sydney�??s Little Bay: to test their eco-driving ability in the Volkswagen Think Blue Challenge.

The man educating us on how best to drive efficiently opened with the admission that he spent a past life burning fuel at a rate of 75 litres per 100km blasting Mitsubishis through forests, 1990 Australian Rally Championship and four-time Group N category winner Ed Ordynski.

As Ed explains, while economy means little when the clock is running, driving efficiently between stages allowed him to carry less fuel and therefore reduce the weight of his car, giving him an advantage over some rivals.

The challenge before us is simple enough. Drive four different Volkswagen models as efficiently as possible over a 20km circuit, two clockwise and two anticlockwise.

Awaiting CarAdvice�??s maiden run is a Volkswagen Caddy Maxi Van TDI250, intimidatingly described as the most challenging car in the field by our gravel-conquering mentor.

The Maxi Van is powered by a 75kW/250Nm 1.6-litre four-cylinder turbo-diesel engine and paired with a five-speed manual transmission. Brake energy recuperation and engine start-stop from Volkswagen�??s BlueMotion suite of technologies contribute to an official combined cycle fuel consumption of 5.2 litres per 100km. Worryingly for us, the best Ed could manage in his benchmark-setting lap was 5.3L/100km.

From the outset, it�??s important to acknowledge the difference between the function of the accelerator pedal in a petrol car versus a diesel. In simple terms, the throttle in a diesel injects fuel into the engine, where in a naturally aspirated petrol-powered car pressing it opens the throttle butterfly to allow more air into the engine.

As a diesel manual, the advice for the Caddy Maxi Van is to keep throttle inputs light and to a minimum. That may mean dropping back gears on hills if the engine starts to labour in higher ones, counter to the common belief that low revs neatly equals low fuel use. It�??s worth noting, particularly when driving in Little Bay�??s late-weekday-morning traffic, that the engine stop-start system only activates when you select neutral and take your foot off the clutch.

After idling for a few minutes to get the engine up to its ideal operating temperature �?" the trip computer isn�??t officially reset until we crawl up to the starting line �?" we take a last look at our drive map and set off.

Progress is slow as we gingerly feather the throttle up an early incline, allowing the torquey 1.6-litre to get out of its initial lag zone and into the meat of its torque band. Sloshing of fuel is heard in the Caddy, thanks to the stripped out cargo area, the subtle reminder to drive efficiently made even clearer thanks to all fuel-sapping auxiliaries switched off �?" no air conditioning, no stereo, and windows up to avoid any aerodynamic catastrophes.

Forward thinking is vital, as is getting every last spark of amber out of traffic lights that seem to instinctively know that we�??re on an economy run�?�

A missed turn forces us to perform a painfully throttle-heavy three-point turn across a busy street agonisingly close to the finish line, but the end result is a good one. At an average of 4.2L/100km, we�??re an impressive 1.1L/100km or 21 per cent more fuel efficient than Ed, and CarAdvice takes the early lead over the field, all of which manage 4.5-5.5L/100km. Early points to light throttle application �?" and a light breakfast �?" then.

Next up is the Volkswagen Up!, a car that demands a completely different driving style to maximise its economy potential. The 55kW/95Nm 1.0-litre three-cylinder five-speed manual Up! doesn�??t feature start-stop or any other mechanical eco-aids, leaving efficiency solely in the hands �?" and feet �?" of the person behind the wheel. Unlike the Caddy Maxi Van, the key in the petrol manual Up! is to keep the revs low, with less emphasis on moderating throttle position.

As one of our favourite city cars, we get a little lost in the moment sliding behind the wheel of the Up! and realise 3km into the loop that we�??ve got the driver�??s side window down and are whistling to tunes playing through the stereo. A frantic mashing of buttons to kill the auxiliaries is followed by the hollow feeling that all is lost, though a good run with lights and traffic restores our confidence in the back half of the circuit.

The majority of the drive is spent in top gear, where surprisingly the pint-sized engine, which delivers peak torque between 3000-4300rpm, doesn�??t feel too tortured dragging along the car�??s 880kg mass and the regrettably weedy 71kg frame of its driver at speeds rarely exceeding 50km/h.

We roll down to the finish line feeling better and are validated with an average of 3.2L/100km, which is 0.8L/100km better than Ed managed, 35 per cent below the official 4.9L/100km combined cycle figure, and once again sharper than the rest of the field, which managed 3.5-4.3L/100km. So far, so good.

CarAdvice slides behind the wheel of the all-new Volkswagen Golf next, our benchmark small car and another of our favourites with which we happily reacquaint ourselves. Ed explains the Golf 103TSI Highline is the most like his rally cars with its 103kW/250Nm 1.4-litre four-cylinder turbocharged-petrol combination.

Once again we�??re warned to keep the revs low, though this time it�??s to avoid the fuel-chugging practice of the turbo getting on boost. Equipped with a seven-speed dual-clutch �??DSG�?? automatic, it is also critical to use the gearbox in manual mode to avoid the transmission kicking down gears and sending up revs.

Our final car, the 130kW/380Nm 2.0-litre Volkswagen Passat 130TDI Highline diesel, again presents its own specific challenges, but is also the best armed with aids to improve efficiency. The Passat six-speed DSG uniquely features a �??coasting�?? function, which automatically de-clutches the engine, countering the effects of engine braking, and uses the vehicle�??s momentum to save fuel.

Coasting only operates when �??drive�?? is selected, however, so remembering to switch between the gearbox�??s manual and auto modes is essential.

With the routes now memorised, our attention is solely fixed on driving, which in the DSG equipped duo effectively feels like 40km of nudging the gearlever forwards each second to try to coax the transmission into taking a higher gear.

With less control over the shift patterns and engine operation, we�??re hesitant as we complete our runs in the autos and head in for the presentation ceremony. Figures of 4.7 and 4.8L/100km for the Golf and Passat respectively are our highest for the day, and leave us anxious, despite undercutting the official combined cycle figures by 1.0 and 0.6L/100km.

The tension is needless, however, as CarAdvice finishes top of the class once again with both cars, beating a spread of 4.9-5.9L/100km in the Golf and tying for the win, and beating a trailing 5.0-5.6L/100km field in the Passat.

A 4.2L/100km average across all four cars sees CarAdvice burn just 3.28 litres of fuel to complete the cumulative 80km for the day, heading a pack spanning 4.5-5.1L/100km, with Ed positioned around the middle at 4.9L/100km.

The take-home is an obvious one: while there are some brilliant systems to aid your car�??s fuel efficiency, the biggest variable is the person behind the wheel. Understanding how your vehicle works, employing a few general eco tips and most importantly having the right attitude has the potential to save you serious time and money at the bowser and reduce your car�??s environmental impact.