The Pontiac Solstice GXP with the turbo four has an EPA fuel economy rating of 19 city/28 hwy when mated to a 5-speed manual. Not bad at all for the performance it delivers, but that same drivetrain in the bigger, heavier Camaro isn't likely to give you equal returns in terms of fuel consumption. Over at AutoblogGreen, Sam notes that the 2.0 turbo's lighter weight relative to the six- and eight-cylinders the Camaro's going to launch with should help somewhat. He follows by reminding us that GM's next-gen mild hybrid system will work with RWD cars and predicts that we'll see a 2.0T hybrid Camaro by 2011 or so. This would dovetail neatly with the first phase of the new CAFE regs, and we're sure GM would find a way to engineer a hypothetical turbo/hybrid's fuel economy numbers so they'd play nice within Uncle Sam's rules. Great.
The issue with all this talk of four-cylinder turbos and hybrids for a muscle car (along with attempts to redefine the class and reset expectations) is that everyone conveniently overlooks just how good the existing V8 is. In the 2008 Corvette Coupe, the big bad 6.2L LS3 is rated at 16 city/26 hwy. Hardly a guzzler in the traditional sense, the V8's rating isn't that far off from the direct-injected Ecotec turbo. Furthermore, the V8's fuel economy comes with 430 horsepower and 424 lb-ft of torque. Those are numbers befitting a muscle car like a Camaro. Who's to say a direct-injected LS-family V8 with efficiency tech like hybridization and/or cylinder deactivation wouldn't be just as effective at meeting the federal fuel economy requirements that begin taking effect a few years from now? You could potentially satisfy the government-created CAFE gods without giving the customers who want actual, traditional muscle the finger in the process. Yes, the consensus seems to be that smaller engines will be a necessity across the board in the new CAFE era, but let's not summarily ignore the bigger ones just because they're big.