Toro Rosso has the least powerful engine on the grid according to Mercedes technical boss Paddy Lowe, with Renault and even Honda having caught up and overtaken in the power stakes.
The Faenza based outfit is the only team to be running a 2015-spec unit after a late switch from Renault to Ferrari.
Lowe, citing Mercedes' own GPS data, suggests Renault and Honda – both of which struggled last year and were off the pace of the Ferrari unit – have made significant gains over the winter and have now overtaken the power unit used by Toro Rosso are in fact not far off the '16 Ferrari and Mercedes units.
"You may not know this, but the engine with the least power on the grid is actually the Ferrari in the Toro Rosso," Lowe told ESPN.
"The Renault and the Honda are not so far behind the [current] Ferrari and Mercedes, so there is not a lot of difference now between the power units," he added.
"Even the worst engines in Formula 1, and people complain like hell about them, are still fantastically efficient by any absolute standard. They just happen to be one or two percent worse than the best engines."
