Yes but that has been the case the past few years, the Renault engine is more fuel efficient. This is a new trick though, if Brawn is correct.
In previous seasons, I believe they were 'cold blowing' the diffuser, rather than 'hot blowing' - ie purely forcing air over the diffuser rather than exhaust gases, which allowed them to use less fuel. Now that they cannot blow the diffuser, this systems allows them to continue light fueling.
I believe the cold blowing is part of the reason why RB to turn the phrase 'called bullshit' on the FIA banning blown diffusers for 'environmental reasons', as 'cold blowing' does not require the wasting of fuel that 'hot blowing' does
There will be people far more knowledgable than me who can confirm but I believe that is correct.
Edited by jamiegc, 21 March 2012 - 17:49.