This year, the German marque is fighting for title spoils against only Renault and Ferrari, but Japanese carmaker Honda is returning to the fray in 2015 as McLaren's works partner.
"There are pros and cons (for Honda)," said Cowell.
He is referring to the fact that Honda is missing from the grid in 2014, the very first season of the all-new turbo V6 era.
"Ferrari, Renault and Mercedes have the experience of winter testing and the grands prix this year," Cowell told Germany's Auto Motor und Sport.
"We know based on facts what the issues are and how to solve them. Honda can only watch," he said.
"On the other hand, we face a challenge in that we are continuing to develop the current engine in the context of what is allowed, and simultaneously we need to prepare for the 2015 homologation next February," Cowell explained.
"So Honda has the advantage of being able to learn through photos and analysing the performance of the engines whilst concentrating fully on 2015," he said.
"They are gaining knowledge free of charge, but not in the depth of the three (existing) manufacturers," added Cowell.