Complex sentence: During the Portuguese rally, Toivonen is often reported to have tested his Delta S4 at the Estoril circuit and to have set a fastest lap time that would have qualified him in sixth position at the 1986 Portuguese Grand Prix.
Split into simpler sentences: During the Portuguese rally, Toivonen also tested his Delta S4 at the Estoril circuit. It is often reported that his fastest lap time would have qualified him in sixth position at the 1986 Portuguese Grand Prix.