The latter Italian outfit, however, is calling on the FIA to relax the so-called 'engine freeze' regulations, whereby substantial elements of the power unit are not able to be changed except for cost, reliability or safety reasons.
But Renault ambassador, F1 legend and quadruple world champion Prost tips the French brand to make big progress for 2015 within the existing rules.
"When I talk to the people from Renault Sport, they say they have the opportunity to make changes to the power unit and that everything will be fine," he told the Russian website f1news.ru.
Indeed, engine homologation of the power unit is in fact being phased in, with a system of 'tokens' meaning that Renault and Ferrari could, in theory, enter the 2015 season with an engine altered by a factor of 48 per cent.
"Of course," Prost said, "the restriction (in the rules) should not be too strict, because otherwise those who did everything correctly from the beginning will just win forever.
"This is not what we need (in F1)," the Frenchman added.
"It does seem possible to improve the engines well enough, but let's see how the situation develops," added Prost.