How well do plug-in hybrids really deliver?
Looking at the pure facts and figures, Volkswagen’s Golf GTE boasts over 200 combined hp of a modern, top of the line gasoline engine all the while consuming – well actually not even sipping but merely wetting the lips at 1.5 l/100 km (67 km/l or a meagre 156 mpg). If you factor in the consumption of the sound system or windshield wipers, one must get the impression, this car would generate energy as it drove along. Some kind of perpetuum mobile or overunity device.
Pricewise, this wondermachine commands an additional 5.000 €. Additional to the base price of the Golf GTI, not the baseline Golf! Basically a premium to proceed from the normal bread-and-butter Golf GTI powerhouse to go green. Autogas Journal was intrigued by this and looked into the value for money which Volkswagen delivers on this top notch “green” sports hatch.
Modes of play
Under the hood the ubiquitous 1.4-litre is paired with an electric motor of 75 kW maximum output under one “yoke”. This power packing combination is topped off with assorted cutting edge electronics and wrapped in the smart trim of the GTI-line. The interior floor lighting has been changed – fitting the electric theme – from red to “electric blue”. Including all the technical gadgets does come at a cost; the fuel tank’s capacity was reduced by 20 %, from 50 to 40 litres. This should be no problem, the official figures state a cycle consumption of only 1.5 litres per 100 km, don’t they? This should add up to a still impressive total range of 940 km. It does, theoretically, the fine print narrows it down and precises its range statement to be only applicable to the “new European driving cycle for hybrid vehicles”. An important information as we will find out in a short while.
The test driver’s impression reflects that Volkswagen allows this model to rightfully sport the letters G and T in its designation. Naught to 100 is achieved in only 7.4 seconds impressively demonstrating what traction control is actually good for. The brisk acceleration throughout the entire range propels the car rather quickly to its top speed of 217 km/h. This spritely performance is only available in the GTE-mode. The one of three available modes which makes no compromise to the environment purely focussing on performance. The engine sounds coarser and the electronic controls of the DSG double clutch gearbox move the shift points far up the rpm curve. In normal mode, performance levels drop down to the level of the normal TSI. The different submodes (“gliding”, recuperation and direct injection) aid the driver in managing his energy resources, drastically increasing range. The “efficiency manager” keeps anyone in the car informed about how well the electronics are doing their job.
Volkswagen advertises the electric mode as the real added value. However, the avid GTE-pilot will need a wall outlet to top off the batteries first before he starts. Three to four hours after making this necessary connection, the batteries indicate an available charge of 100%. In theory this equates 50km in pure electric mode. In theory. Brutal reality check: 38km, not more. Sound system, air conditioning, and a few other gadgets all serve themselves from the same battery. After only a kilometer the remaining range has dropped to 32. A rate at which most won’t even make it to the bakery in town in pure electric mode. The test driver confirmed that it is very silent (the author’s personal experience with a Tesla Model S confirms), the lacking engine sound actually makes the ride more enjoyable. Top speed is limited to 130 km/h in pure electric mode, in contrast to the unlimited mode where the TSI engine is called in for assistance. The “express” mode described further above unleashes the combined full power of both internal combustion engine and electric motor.
The great surprise
The sportive GTE-mode comes at a cost. One morning, on a deserted Autobahn, the test driver was able to let the car off its leash and submit it to a slightly more sportive test. A test in which the cost of the dynamic driving is presented in very clear figures. Instead of merely sipping the fuel at the advertised rate of 1.5 l/100km the tiny engine developed an incredible thirst for gasoline and managed to burn a mind boggling 16.5 l/100km, worthy of old “American iron”, albeit without the notorious burbly exhasut note nor the muscle-car sex appeal. Any car built in the past 15(!) years capable of similar performance would better this technological wonder. The author’s former Subaru Legacy LPG from 2006 would consume an absolute maximum of 14 l/100km of Autogas at the same top speeds with a full time all wheel drive. It is safe to assume that the “real” GTI would have at least equalled the performance at a far reduced consumption. Over the test distance of 96 km the battery chipped in 2.9 kWh of electricity. Charging this battery consumed 8.7 kWh, which – considering the 32 km real range – at the current cost of roughly 29 ct/kWh, yields an average cost of 7,83. The baseline TSI devoid of all weighty hybrid ballast will surely do better. A CNG, LPG or diesel version will win hands down with one arm behind their back easily making the case for the internal combusion engine vs electric vehicles in real life.
At least the electric side will bring the win? After all the main argument for electric vehicles was the lower CO2 emisisons. The amount of electricity drawn out of the wall outlet and not that what manages to stay in the battery is what drives CO2 emissions. Instead of the 2.9 kWh used by the electric motors, the 8.7 used to charged the battery are balanced with 575 g/kWh amounting to a grand total of 5,002 gCO2 for the above mentioned 32 km. Amounts to 156 gCO2/km. For an electric vehicle. Even the same car on gasoline will do better!