At the Nurburgring 24 hour endurance race on 23 and 24 May, Volkswagen will field two Scirocco race car concepts that have been modified to run on compressed natural gas (CNG). Last year, VW clinched a one-two victory in the 2.0L turbo class even before the Scirocco's market launch with the standard petrol version of the GT24, and this year the carmaker intends on highlighting the performance potential of more environmentally-friendly fuels.

The two Scirocco GT24-CNG 2.0L turbo engines powered by natural gas deliver nearly 300hp (225kW). In addition, the "factory" team will also field three further Scirocco GT24 cars powered by 2.0L turbo petrol engines in the classic endurance race.

The Scirocco GT24 has already proved its strengths as a complete sports package by winning in its class last year. This year, VW is taking a step forward by using two different engine concepts in the hope to determine ideal efficiency, dynamics and reliability.

For the CNG engine, VW primarily focused on the fuel induction system of the unit as well as pushing the turbocharger to the limit in terms of stable temperature. The benefit of using CNG, as opposed to petrol, is 25% lower carbon-dioxide emissions and almost no particulate matter or fine dust.

The use of the Scirocco GT24 race cars also serve another purpose. The aggressively styled race cars provide a hint as to the final design of the upcoming Scirocco R20, which has been captured recently testing at the Nurburgring and is due to go on sale by the end of the year.