Golf GTI vs. GTD and Scirocco TSI vs. TDI: Diesel or petrol? Saloon or Coupé?
Diesel or petrol? Saloon or Coupé? At VW, four engine variants compete for the favour of the sports driver: the Golf GTI and GTD and the Scirocco 2.0 TSI and TDI. Who best fulfils drive dynamics requirements?
Doesn't that sound enticing: the VW Golf GTD is the VW Golf GTI for frequent drivers – the same driving fun, but significantly lower consumption and upkeep costs? The same would then presumably apply for the VW Scirocco, the Golf-based sports coupé, if you like; VW offers it in a petrol version with 217 HP and a diesel version with 181 HP. But do the self-igniters really generate the same driving fun?
VW diesels are more efficient, but much more expensive
With regard to the fuel costs at any rate, the question asked at the start of the test is quickly answered with a yes. Switching from the VW Golf GTD to the VW Golf GTI means, on average, switching from 8.0 to 10.1 litres per 100 kilometres, while moving from the VW Scirocco 2.0 TDI to the TSI represents a leap from 8.4 to 10.2 l/100 km, not forgetting the cheaper price per litre that diesel enjoys in on the continent.
Yet, first of all, talk among the augurs is that fuel is set to become much more expensive. And secondly, VW charges significant additional cost for the diesel models. In the case of the VW Scirocco this is around 1,200 Euros – the equivalent in petrol could mean a few exceptionally fun kilometres in the VW Scirocco 2.0 TSI.
But we'll start the test with the VW Golf GTD. It has done away with oil burner character of its forefather altogether. Only trained ears will hear a knocking – and primarily during the cold run phase at that. As soon as load is applied, a deep growl drowns out any combustion-induced staccato tones. A sound generator transport it clearly into the interior of the VW Golf GTD. This should move even outspoken diesel-phobics. It will at least appease any reservations from those that reject a self-igniter primarily on account of its harsh accent.VW Golf GTD hangs softly on the throttle
Another peculiarity of the diesel, on the other hand, meets with little criticism: its high and early engaging maximum torque. And so the diesel hustles boldly, pressing 380 Nm against the crank shaft, and the VW Golf GTD rages staunchly forwards. Those who now, at 2,500 rpm, choose to gear up will once again surf the Nm wave in the next gear.
Sports drivers will, however, want higher revs, and in this respect the VW Golf GTD only provides grounds for criticism in the test: it hangs softly on the throttle. It quickly seems to run out of air, and turns without giving the impression of power. It also quickly runs out of breath on the motorway. IT slogs its way past the 200-km/h mark and then has to back down in the face of the air resistance. The VW Golf GTI is far from finished at this point – it easily tops it in the test.
In so doing, it struck out from the lower rev range like a bull. At low engine speed, its turbocharger already supplies sufficient air to the combustion chambers that it sends the maximum torque of 350 Nm to the gearbox at just 1,500 rpm – thus 250 rpm earlier than the diesel.
The VW Golf GTI pushes even earlier than the GTD
It has been a long time since low-speed driving has been a diesel USP; with turbo-charged petrol engines having come on in leaps and bounds, making up leeway and in some cases out-performing the diesel variants. The VW Golf GTI can at least be driven lazily on the gear stick like the Golf GTD and in so doing even presses more heavily, as the elasticity values in the test prove. Here the petrol engine is consistently in front, sometimes even outclassing the diesel – the difference is even more clear in the mid rev range, when the two-litre turbo in the VW Golf GTI gets its second wind. Its voracity only eases shortly before the red area. But at this point the VW Golf GTI has well and truly wiped the floor with the GTD.
Incidentally, it is a similar case with the VW Scirocco – only more dramatic. In the test, the 2.0 TDI looses out even more emphatically to the 2.0 TSI. By a speed of 100 the petrol model is already way out in front, building on its advantage as it reaches 160 km/h; and for 0 to 200 km/h the diesel requires 17.5 seconds longer!
Thus, on the Hockenheim Short Circuit, the VW Scirocco 2.0 TDI simply feels weak. Here, where compact sports cars around the 200 HP mark are practically always required to go full throttle, the below average zeal is even more evident. To squeeze every last drop out of the self igniter is no use as even early gear changes don't unleash euphoric thrust. In the end this results in a drastic time difference, which is in keeping with the feeling on the race track itself. The diesel lags almost three seconds behind, and is even a tenth slower than the VW Golf GTD – you continually notice the need for more power.The VW Scirocco is more at home on the race track
Here the VW Scirocco is essentially much more at home on the race track than the VW Golf. Its lower centre of gravity allows it to steer more precisely, whereby its more active handling makes a crucial difference. To start with, the chassis inspires with its slightly understeer-prone handling in the event of load changes. The steering is in no way inferior and conveys a great deal of road contact, without responding excessively sensitively.
Yet in the VW Golf GTI in particular, it is evident that the zeal shown by the rear of the car is not in keeping with the ESP. It can only seemingly be disabled, whereby pressing on the corresponding button only raised the threshold value – however the stability control in the VW Golf GTI cannot be completely disabled. It intervenes, braking as soon as a certain side slip angle is reached, and only releases the power again when the front wheels are straight.
Those who want to achieve viable times must therefore remain slightly below the control threshold and carefully apply the accelerator at the apex of the corner, as the drive system will generally deliver more torque to the front axle than it can transfer to the asphalt. Here the limitations of a pure front-wheel drive car on the race track are evident; with improvements only promised by sports tyres and a mechanical lock, as found in the GTI Performance. XDS, the electronic version, also juggles from left to right with the Newton metres, but in so doing reaches its limits on the Short Circuit.
All four VW models - regardless of whether petrol or diesel, saloon or coupé - require a clean driving style and careful braking; while the use of ABS and the associated intermittent opening of the brake callipers inevitably result in the anchor being cast. This in turn results in the following peculiarity: the front-wheelers push over the front axle when exiting the corner, which basically destroys the ideal line.
VW diesels heavier than the petrol models
For the Scirocco and Golf VW offers adaptive shock absorbers for both the respective diesel and petrol versions. This option is a convincing alternative to a classic ports chassis: in Hockenheim you can use the Sport setting to reduce tilt and roll, but you can also make use of the godsend of forgiving damping when cruising over long distances (Comfort setting). On poor quality country roads the latter also provides a traction advantage that should not be overlooked – as smoother front wheels ensure firm road contact.
On country roads, incidentally, it also becomes clear that the diesel engines, with their higher weight, impose a slightly heavier load on the front axle, which is therefore detrimental to the front/rear balance. Thus, in the self-igniters the limit range announces itself a touch earlier by slipping in the direction of the exit of the corner.
Ultimately, everything except the fuel consumption argues against the two diesel engines, which are rated equally in the evaluation. The petrol engines fulfil the criteria considered vital by sports drivers much better. Here the VW Scirocco 2.0 TSI outdoes the VW Golf GTI by one point in the test, which comes down to its better lap time and is in keeping with the VW world view. Ultimately, sports coupés should always be faster than saloons – this is a matter of honour.
Date31 May 2015