Formula 1 teams faced fresh fuel system checks at the Monaco Grand Prix as part of a clampdown by the FIA.
Christian Horner sees more gains to come thanks to a fuel.
A theory has been bouncing around the paddock that Red Bull's Total fuel might be a contributing factor.
Many fans would welcome a reversal in thinking from the FIA.
The manufacturer of a crucial fuel flow sensor is now ready for F1's 2014 season.
"Fuel was mentioned purely for illustrative purposes" - FIA spokesman
Dr Helmut Marko insists there is no conspiracy at all
According to report, Mark Webber was low on fuel when Vettel tried to do an overtake