Volkswagen Polo
Volkswagen Polo and Golf models are among the petrol cars affectedGetty

Volkswagen has been forced to announce that while investigating the diesel emission crisis, it found 800,000 of its petrol cars had also cheated CO2 emission tests. The news sent the carmaker's share price plummeting by 10%, the fastest pace since the diesel emission fraud was first revealed.

After the scandal came to light, many diesel VW owners wanted to know if their cars had the fraudulent software installed. The carmaker has since sent out recall letters to owners of the vehicles affected.

But how can you check if your petrol car is involved in this latest crisis? VW launched a self-service checking system for people to find out whether their diesel car had been affected by the emissions scandal.

So far, such a service has not been set up for the petrol cars but there is a way for owners to check if their vehicle is likely to have been affected. As far as we know, the cheat "inconsistencies" has only discovered in cars with 1.4 litre engines.

Volkswagen's Golf and Polo models have these engines of this size installed, as do selected Skoda and Seat vehicles. For Audi vehicles, the A1 and A3 models are more likely to be affected. However, the wait is on for VW to release more information on the petrol vehicles that are involved.

"This is a painful process, but it is our only alternative. For us, the only thing that counts is the truth. That is the basis for the fundamental realignment that Volkswagen needs," Volkswagen CEO Matthias Müller said. "The Board of Management of Volkswagen AG deeply regrets this situation and wishes to underscore its determination to systematically continue along the present path of clarification and transparency."