 The Berta Mk3 was used exclusively during 1987, until the championship was opened up to other suppliers in the following year.From 1988 until the mid-1990s, chassis from Reynard, Ralt, TOM's and Dallara were in common use, but at that point, Dallara's increasing performance advantage had the same effect in South America as it had in Europe, and it became the de facto choice.Since 2005, the series organisers have sought to keep budget requirements under stricter control by using a "control specification" engine, which is produced by Berta.