Excellent post, mpg. In the world of engineering, you set a target (in this case an engine with power output around 400 hp). You make different experiments, measure the outcome and if tied, the simplest solution is the best (in this case the simplest is also better by the numbers, as the LS6 is far more fuel efficient). Porsche uses this (worse) technology however, as they have the tooling and production lines for smaller engines and more importantly, because of tradition. Also, in racing applications, the displacement is often limited, so this is where the hp/liter finally starts to mean something and this form of small engine tradition becomes actually useful. But whatÅ½s the "actual usefulness" of a racing application? There was a test in C&D where 911 Turbo was beaten on track by a Z06. GT2 is a suped up 911T so in turn itÅ½s probably a tad faster than the Z06. Funny note about a Porsche being an economy car of 65 years of evolution - itÅ½s true, as the Porsche was evolved from the good ole Volkswagen Beetle, which is rear-mounted boxer engined family car (info for those who didnÅ½t know). Getting back to original topic, all the patriotism aside, as IÅ½m from Northern Europe: Even if money was no object, or the GT2 was the same price as the Z06, I would first take the Z06. 1) GT2 looks like an egg on wheels. 2) I donÅ½t want to be associated with the yuppie guys in Armani suits. 3) Z06 can also be a comfy ride whereas GT2 is more an all-out racecar. 4) Where I live, Porsches are more common than the Vettes (Porsches are still considered more prestigeous, however). But if the money was no object, why not buy both? PS. LS6 and LS1 differences are in the valvetrain, where LS6 has a lightened one. Block is the same.