The FIA has revealed the token spend for each manufacturer over the winter, with Ferrari using up the most of its allocation and Renault holding many over for the year ahead.
'Tokens' were introduced at the start of the 2014 season as a way of allowing some development to take place on the engines, with different areas weighted with a greater value than others.
With 32 development tokens to spend, Ferrari has spent 23 tokens – leaving it with a relatively meagre nine to use in the coming year. Mercedes is up next having spent 19 tokens, leaving it with 13, while Honda has used 18 to leave it with 14.
By contrast, Renault – which left a lot of its development on last year's engine until late in the year -, has spent just seven tokens, leaving it with 25 for the year, though the French firm, which is returning to F1 as a constructor this year, believes it has made a big step forward with its power unit over the winter.
25 tokens remaining (7 spent)
14 (18 spent)
13 (19 spent)
9 (23 spent)