Millbrook backs True MPG test’s True MPG real-world fuel economy tool is now using a new measurement system with support from leading automotive technology test centre, Millbrook.

Starting this month, the True MPG test process will now be conducted by Millbrook’s experts in a test laboratory and to a real-world route mapped out by’s reviews team.

The test process has undergone robust benchmarking with Millbrook to make sure that the resulting data, accessed by more than two million visitors to the What Car? website every month, is fully reflective of real-world figures and much more realistic than the official fuel economy figures quoted by car manufacturers.

Importantly, the strictly controlled conditions under which the tests are conducted – modelled on a real route driven by the What Car? team that takes in town, rural and motorway roads – ensures repeatability within one per cent for all CO2 emissions and fuel economy work.

All data produced by the new process will be wholly owned by and will continue to be a vital part of the suite of consumer-friendly tools offered by the UK’s biggest car-buying brand.