Part of the Corvette's fuel economy can definitely be laid at the door of the pushrod engine.
The two-valve combustion chamber that makes for less flow at high rpm and less hp per liter than other cars makes for better low-rpm running... and with direct injection and higher compression, it gets even better. The new 6.2 has nearly the same torque as the old 7.0.
And the simpler hardware compared to other high-performance engines makes it very compact and light.
Perhaps going forward, it's better to discuss horsepower per pound of motor instead of average horsepower per liter... as the liter part doesn't always translate to lower consumption (at speed) and the peak horsepower part doesn't tell you a whole lot about the engine's performance.
Just imagine, though... if you could get similar benefits in terms of economy out of a small motor built the same way. Say, a Volt range extender made of a V2 cut out of the LT1...
