Ford's (F 0.08%) recent sales results have showed the Blue Oval gaining market share in the U.S. – but they've come with something that has some investors worried: large fleet sales, traditionally a low-profit way for automakers to keep production numbers high.

Over 30% of Ford's U.S. sales are to fleets, and that has some investors concerned that Ford is missing out on profits or "juicing" its sales numbers. In this video, Fool.com contributor John Rosevear breaks down Ford's fleet numbers in more detail – and looks at whether Ford's big fleet sales are a sign that its recovery is stalling.