I have wanted a G8 GT since I saw the first commercial, and have been reading these forums since I found them. Although I do not own a G8 currently I wanted to join just to get in on the discussions.

You guys are great and a wealth of knowledge so when my wife gives in (probably 2010 I'll be able to get a used 2008 ) and lets me buy one I already know what products have been installed, tested and so fourth.

One question, what grade of fuel are most of you guys using (stock or with mods)? Notice any difference with drivability between regular and premium?

92+ octane in performance V8's IMO.

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08 Stealth Blue G8 GT - Fully Loaded Plus Some
http://i297.photobucket.com/albums/m...P8060079-1.jpg
NEP CAI with VMS HSRK, Mobil 1 0W-30 Advanced Fuel Economy
18% Tint, Blued Out: Reflectors, Badges, Gauges, & Center Stack
A Few GRRRR8 Mods, 12" RF Pro, Audio Control EQX, PPI PC 2300 WSE

I know GM recommends premium but says that you can run regular. Being gas prices are so high and that this would probably be my daily driver just wondering if there would be any adverse effects if one would run regular (knocking, pinging, etc...) gas. Horsepower would be a little less but if its not going to the track regular should be fine...right?

I got almost 7,000 miles on my IOM G8 GT
and have used only regular gar so far. I have
noticed no problems at all. I have no mods yet.
Get about 25-27 M.P.G. on the highway.

I have a LOT of mods, run premium, but truthfully the gas mileage is so good on normal driving that for the few $$ difference, I want the POWER!

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2008 LIQUID RED SPORT/PREMIUM. VECTOR ECM/TCM TUNE, HSRK, ROTO-FAB AIR INTAKE, POWERBOND 25% PULLEY, ARH 1 7/8 HEADERS, DASHHAWK, LS3 HOT CAM AND DOD DELETE COURTESY OF PACE PERFORMANCE, MISC ENGINE INTERNALS COURTESY OF LIVERNOIS MOTORSPORTS, PUTTING THE POWER TO THE GROUND: PEDDERS SUSPENSION COURTESY OF PEDDERS USA/WRETCHED MOTORSPORTS, TQ CONVERTER COURTESY OF CIRCLE-D, MULTIPLE GRRRR8 MODS.

I run strictly 93 Octane and avg 20-22, no less than 18 strictly in city, and 26 on the highway....And that's always aggressive driving.

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Ign. Orange, 20% Tint, 19" Zinkin Z27 Sofins, American Racing Header System, Powerbond Underdrive Pully, 160 Degree Thermostat, New Era Performance CAI, Throttle Body Port, and Engine/Trans Tune, GRRRR8 CAI Airflow Mod, GRRRR8 Intake Cover Mod, Mobile 1 Synthetic, K&N Gold Oil Filter, VMS HSRK, NEP 228/240 Cam, Kooks Mufflers from Maryland Speed! 347 RWHP 360 Torque, 12.6841 1/4 Mile @ 114.74 MPHComing Soon: Pedders Susp.

No mods, but I've also been running premium.

We bought my wife a Tahoe at the begining of 07 and it has AFM, usually run regular but sometimes when she's not looking I will but mid-grade in it. She gets about 16-18 mpg but its all city driving and the Tahoe ways like 5600 lbs. My wife wants me to get an Accord (4 bannger) I will only get the V6, the thing is it only gets like 4-5 mpg more then the G8 GT so the PROS vs. CONS = I likle the G8 better.

I have no mods and I also use premium. I figure it's only an extra $4 a tank.

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GM does recommend premium? I have scoured the manual and cannot see that anywhere. In fact my manual says they recommend 87.
I'd but the higher octane if I could find any literature that said it gave me something back.
(So I do know some of the tuners and guys with mods say they need the higher octane - but for a stock car all I am hearing is no diff between 87 and 93).

I run premium in the G8. It's not that much of a difference when filling the tank.