THE CRISIS engulfing Volkswagen showed no signs of abating over the weekend.

On Saturday, Switzerland banned sales of all VW models implicated in the so-called ‘dieselgate’ scandal.

That was bad enough, but yesterday German authorities said they were giving the group until October 7 to prove its cars meet EU emissions regulations. If VW fails to do so, they are poised to withdraw sales approval for some of the company’s best-selling models in Europe’s biggest car market.

VW’s actions have rightly focused attention on the shoddy testing practises used to rate vehicle exhaust emissions and fuel economy. Last week’s revelation that some VWs have a software algorithm that can cheat bench tests merely confirmed what most drivers already knew: that ‘official’ laboratory tests do not reflect real-world use.

VW’s actions, reprehensible as they may be, were rooted in the knowledge that every car manufacturer tries to game the tests.

Bodywork gaps are taped up, tyre pressures are changed, alternators are disconnected and carefully chosen lubricants are used to help the engine run more efficiently. Taken together these – entirely legal – ruses can improve a car’s mpg by up to 50 per cent.

By allowing this manipulation, it is the regulations – and the way they are implemented – that have been found wanting, not the car manufacturers.

New testing procedures – which have been talked about for several years - are now likely to be rushed in.

We welcome anything that makes pollution and mpg figures more realistic. A transparent testing regime is the only way drivers can make a fully informed choice about the cars they buy.

Ultimately, if this scandal makes drivers think more carefully about the type of car they drive there could be a positive outcome, not least for Nissan, which builds the zero emissions Leaf electric car at its plant in Sunderland.