maybe a little but running on 87 octane will make it a little bit cheaper on fuel. As I said before, intake, tune and maybe exhaust and I would expect over 400 crank hp out of it.

It will not go against BMW of any flavor. Its as big as a 5 series, a little shorter and lighter then a Charger, but quality matches the Germans.
It is matched against the BMW and MB in Europe, but they talk about how its almost half the cost of a 5 or E class and offers just about the same stuff.

V6 will start at under 28k, V8 under 30k. That matches the LX cars's pricing, which it will go against. All the major mags are putting out its review of it. They are just fine tuning it for US spec. The 6spd manual will not get the AFM V8, so they will have to recert a new engine and the Tremec 6060 6spd manual trans, and the 6spd manual will get the gas guzzler tax this time, unlike the GTO which got it on the auto version.

G8 is a touch shorter then the Grand Prix as well. If you are looking for a 4dr muscle sedan, this will be it. Underpowerd? 0-60 times are supposed to be 5.3, which is what the 04 GTO's ran, and damn near right next to the LS1 fbodies as well as the new Mustang GT.
Underpowerd? For 2 tons...not even close.