Red Bull Racing team principal Christian Horner has described the FIA’s modified 2017 engine regulations as “underwhelming” and “weak”.
At the end of last month the FIA ratified changes to the power unit rules to guarantee supply, provide a reduction in cost, power convergence and greater noise.
But Horner is not convinced by the new engine regulations set to debut in 2017 and believes more needs to be done in this area.
"It is a little underwhelming," he said during the FIA press conference on Friday. "It's a very soft agreement between the manufacturers and the FIA.
"It tickles the price, deals a little bit with convergence, the obligation to supply doesn't really apply, so it's a very weak agreement.
"Unfortunately, it's a shame more couldn't be done, but I suppose if you look on the bright side it's better than nothing."
However, Mercedes boss Toto Wolff disagrees with Horner on the matter, believing big steps have been made: “We achieved a major price reduction over two years.
"We have opened up development scope for others to catch up. We have designed an obligation to supply so no team runs out of an engine contract.
“We have found a mechanism how performance convergence could be triggered. Lots of good things, many months of hard work in trying to get everybody on the same page, I think it's a good step forward."
Discussion about this post