Maybe I need to see the episode, but why can't Top Gear give their opinion of the fuel economy with what they actually achieved. They are not the EPA, they are a television show, Tesla can still claim its fuel mileage. Pretty much every car on the show gets picked apart to some degree.
2011 Synergy Green Metallic 1SS Camaro:
RS Package, White Ralley Stripes, Premium Sound.
Mods; Flowmaster Exhaust, Vararam CAI, Pfadt Sport Suspension, Budnik "Ice" Wheels, Nitto Invo tires
Upcoming Mods; Custom grill and badging.