US GP: F1 alters qualifying for Austin with Caterham, Marussia out

With the F1 grid reduced to 18 cars, the old format would have meant that just two cars would be eliminated from Q1 if no change had taken place.

The matter was further complicated by the fact that Sebastian Vettel is unlikely to take part in qualifying at all because of an engine penalty.

In light of the situation, and the fact that the F1 regulations do not cater for a scenario where there are only 18 cars, the Austin GP stewards met on Thursday to discuss what to do.

They agreed that the format would be changed so that four cars would be put out in Q1 and four cars would be put out in Q2, leaving Q3 as a traditional shootout between the fastest 10 drivers.

A statement issued by the stewards said: "Having regard to the principles established in the Formula 1 sporting regulations article 33.1, the stewards decide that the slowest four cars in Q1 will [be] prohibited from taking any further part in the session, and the slowest four cars in Q2 will likewise be prohibited from taking any further part in the session."