Overpowered and under-regulated

I was awakened by this question:

What is the most powerful car to not require payment of the gas guzzler tax?

I have no answer for this so I turn to you, my great encyclopaedia of eccentric knowledge.

Corvette?

That's what came to my mind also, but I was hoping it wasn't top dog.

Just read the new XJ has 510 hp with no gg tax.

I thought the ZR1 escaped GG tax, too, so there's 630hp.

I am out of the know...what is the current GG threshold?

jrw1621 wrote: I am out of the know...what is the current GG threshold?

22.5mpg

damn, ... good thing I'm not buying my Impreza with the gg as a consideration... winter it gets ~ 22 mpg

does the 911 turbo squeak by the GG tax?

i think the answer is Corvette.. a Z06 has mpg ratings in the mid 20's, and the ZR1 isn't much lower than that.

Corvette for sure. Long legs on them. I see 30+ MPG with mine on the freeway. Top off, A/C on, 75 mph, 6th gear.

Mixed driving gets it into the low 20s.