The debut had been planned for the July 16 French Grand Prix, the 11th round of the 18-race season, but the team said events had delayed that to the following race weekend at Hockenheim on July 28-30.
Honda-powered Super Aguri, who only this season became Formula One's 11th team and the first with an all-Japanese line-up, said the new SA06 had passed its mandatory crash tests.
"The initial SA06 design and build schedule with a deadline of the F1 race at Magny-Cours was extremely tight and with no margin for delay in any area of production," the team said in a statement issued at the U.S. Grand Prix.
Super Aguri said the first delay was due to a decision on the specification
"The team increased its working hours even further in an attempt to make up for lost ground but have now decided upon a more realistic launch date of 28th July at the German Grand Prix," said the statement.
The team started the season with a modified version of a four-year-old Arrows while they waited for their own challenger to be built.
Super Aguri have been several seconds off the pace in the races to date and have yet to score a point.
They also had to replace Japanese driver Yuji Ide with former Renault tester Franck Montagny of France after the governing body withdrew the rookie's licence.
(Writing by Alan Baldwin in London)