Sinclair C5 major consumer organisations published sceptical evaluations. The Automobile Association questioned many of Sinclair's claims in a report published at the start of May. It found that the range of the vehicle was typically only about 10 miles (16 km) rather than the promised by Sinclair, and reported that the C5's battery ran flat after only on a cold day. The C5's running speed was more usually around than the claimed , while its running costs compared unfavourably to that of a petrol-driven Honda PX50 moped. The stability, general roadworthiness, and especially the safety of the C5 were questioned, and the
Sinclair Research to Amstrad. Sinclair Research Ltd still exists as a one-man company, continuing to market Clive Sinclair's inventions. On 25 July 1961, Clive Sinclair founded his first company, Sinclair Radionics Ltd. in Cambridge. The company developed hi-fi products, radios, calculators and scientific instruments. When it became clear that Radionics was failing, Sinclair took steps to ensure that he would be able to continue to pursue his commercial goals. In February 1975, he changed the name of Ablesdeal Ltd (a shelf company he had bought in September 1973 for just such an eventuality) to Westminster Mail Order Ltd. The name was changed