The FIA says its analysis has shown that the top three power units, those supplied by Mercedes, Ferrari and Renault, are now within three-tenths of each other in terms of performance.
The governing body conducted detailed analysis across the opening three races of the season in Australia, China and Bahrain, to determine the advantage of each engine. According to their figures, in an identical car, all three would lap the Barcelona circuit within 0.3s of one another.
The FIA didn't confirm which power unit came out ahead, but it's believed both Ferrari and Mercedes are almost level on power, whilst Renault lags behind a little.
"Part of an agreement [between manufacturers] last year was a power unit convergence element," the FIA's Charlie Whiting stated. "It was a system that everyone would assess after the first three races on whether we had power unit convergence.
"This was defined as three out of four power unit manufacturers being within three tenths of a second of each other around Barcelona."
Simulation engineers worked with the FIA's engine head Fabrice Lom to analyse the data, with the engine manufacturers agreeing beforehand that the methodology used to reach the final figure would result in an accurate estimate.
"They sat down and they analysed all this data and, using the method that was agreed by all the power unit manufacturers to derive from these simulations, what it meant in terms of lap time around Barcelona," said Whiting.
"The four engine manufacturers sat down for hours and hours and thrashed out this rather complex method."
Honda's performance isn't part of the convergence agreement due to it entering the sport a year into the V6 power unit era, and Whiting insisted it doesn't mean the McLaren supplier would receive any special treatment to allow it to catch up.
"It wasn’t a matter of helping anybody. It was a matter of establishing the measures that had been introduced, losing the tokens and all those sorts of things that were aimed at helping convergence, had worked."
