I have had a G6 Gt & GXP and now own a G8 GT. loved the seats on the G6 Gt - like the ones on the g8 - still adjusting them. The g6 did not lean on hard cornering but also you felt every bump and slice in the road. The g8 rides much nicer but leans more (me moving in seat is how I tell on leaning) but still holds the road. The g8 is deceiving when you mash the gas. Very little exhaust noise. But you do notice the cars behind you fading in the distance. I had the g6 up to 115 - to 85-90 very quick (hiway about 60 -then mashing gas)after 90 a little time to get to 115. Have not attempted that on g8 as of yet. I expect it to reach 110 without trouble. Want to hold gas to see how the g8 pulls after 100-not easy here in NYC-people just move into your lane and go slower! The sport shifing seems to be the best all around driving feel. To me the car looks like it means business and I like the power thats available to brush off BMW's, Mustangs and a occasional Audi. Enjoy your cars and thanks for reading.

Actually I wouldn't even compare any type of g6 to the G8 Gt...Sure they both have a "G" in the name...but come on man! Those G6's are small potatoes compared to this bad boy...

I wanted to share my comparisons because you are not racing the car every other second. we are in it a lot shopping, work etc. So I just wanted to state what I have noticed between the g6 and g8 other than the obvious.

Here is a video of a stock G8 GT 0-137mph (speed limiter):

YouTube - Pontiac G8 GT 0 - speed limiter

I currently own a G6 GTP and would like to get a G8 GT so I was very interested to read your comparison and observations. Thanks!

I am not quite sure why anyone would try to compare the two but it has happened. I rent cars alot and have spent quite a bit of time in both vehicles to date. I can't stand the G6 for anything more than short drives. The G8 is comfortable, nice handling, and as yet, somewhat unrecognizable,"Hey what kind of car is that?" The main difference,as you all know, is FWD vs. RWD,
Engine power isn't terrible is G6 but torgue steer is. Sorry if I insult anyone here but I had to respond. I am envious,somewhat of you guys that own G8s already but I am holding out for the soon to be introed GXP.

I was not trying to compare one verses the other. apparently everyone is or is taking it the wrong way except for the person before the last reply.. all I tried to convey was I owned a g6 gt-g6 gxp and now a g8 gt. the comparison was for my benefit that I tried to convey. It would be the same if I had a caddy and then bought a buick. I like pontiac and like the g series. I will get the gxp in about 18 months. its ok-i did not get insulted

I never noticed the speedo designations before. You learn something new every day