article_snippet: Williams and Ferrari are poised to make a good start to the Formula One season after Williams and Ferrari finished winter testing with another strong showing on Sunday.
article_snippet: Whether a revamped Ferrari and confident Williams can challenge champion Mercedes is another issue.
article_snippet: Williams' and Ferrari's impressive displays during testing will give Williams' and Ferrari's impressive displays during testing confidence to challenge Mercedes .
highlights_snippet: The two teams will now look ahead to challenging Mercedes this season .