2009 Volkswagen starts installing “defeat devices” on its cars, bypassing tougher anti-pollution standards introduced in 2008. The tougher rules cap legal nitrogen oxide (NOx) emissions.

2013 Researchers from the Internationa Council on Clean Transportation and West Virginia University find abnormalities between the NOx emitted by VW vehicles in lab tests and on the road.

May 2014 The Environmental Protection Agency (EPA) begins an investigation into VW. The back and forth between the two lasts more than a year, as VW argues that third-party tests of its cars were flawed.

September 3 VW admits that it has used sophisticiated software to trick regulators. Its software monitors steering, engine use and barometric pressure to determine whether the car is being tested for emissions.

September 18 The EPA makes VW’s deception public, leaving the Germany company facing up to $18bn (£12bn) in fines, as well as potential cases from the Department of Justice, FBI and the European Union.