The great thing about industry standards is that everyone knows where they are. To take a random example, if one company has to abide by EU Regulation No 443/2009, so must its competitor across the road. If the Regulation is relevant to their business, there is no point in either claiming that they did not know about emission performance standards for new passenger cars.

Thus it goes, too, with vehicle performance information. We all know where we stand on fuel efficiencies of new vehicles, thanks to the Standards. The harmonised test definitions have been scrupulously observed by manufacturers for decades. Any one of the vehicle makers could now offer an expert consultation on how to get around the test requirements.

For the naive or curious, a document called, “100 tips to beat the New European Driving Cycle (NEDC),” takes seconds to find online. A few minutes of reading about pre-warmed vehicles, longer gear ratios and the use of substitute ‘golden parts’ should suffice to make any reader a cynic.

There is some good news. With virtually every vehicle producer stretching test environments way past any semblance of normality and fairness, the result borders upon comical. Everyone tries the same bodges, tricks and ruses to climb the mpg chart… So, relatively, the chart positions hardly change. The only real change is that the mpg figures are now fantasy numbers.

If you just want a level playing field, the NEDC results allow like-for-like comparison. If, however, you want fuel consumption figures with real-world roots, look inwards.

You can see how many miles a vehicle covers during a year. Your fuel costs are easily totalled from existing records. You already keep track of every penny spent on a vehicle, from replacing a flat tyre to changing the cambelt. You know what you paid for it in the first place and can take a fair guess at residual value.

This is not rocket science. Stop trying to compare vehicles based on the makers’ claims, which are known to be nonsense. Switch to using your own data to compile exact whole-life costs for each vehicle, with precise cost-per-mile figures.