On any highway trip I see 30-31 at 70MPH. I can get 33-34 if I have to drop down around 55-60 MPH.

I average 26-27 tank to tank when I include city and short hops.

Can't complain.

I had to run 87 octane one time. All I noticed is the PCM pulls timing like crazy and the power was down. It wasn't an issue at all cruising and normal driving but when I rolled into the throttle and got more than 10 PSI of boost, it would just soften way up. You definitely noticed it. No, no damage, no pinging, nothing - just much lower power. The PCM handles that.

I believe the requirements for premium is for driving experience not durability. Without premium it just can't safely develop the power (boost/advance) and customers would scream about how much power is lost.

 

wow, i dont get anything close to that kind of MPG. My 2010 just turned over 4,000 miles and i commute 80 miles a day country highway with very little stopping. My last tank i drove 55-60 and rolled the throttle and coasted in places and tried to get the best i could and i only got 24.2 mpg. Bone stalk SS.

 

I snapped the pic below about 70 miles into the trip. There were a couple towns I had to slow down for and a couple full out stops but the rest of the time was running between 52-55 MPH:

 

hey you wanna trade engines? lol i wish i could get that...

 

Seems the SS kitted likes the 50=55 range for high numbers....I run a 50 spd limit road to work and see 40's( 44-46 sometimes) all the time,,,but,,,too many lights and idleing..wrecks the overall numbers

 

what I'd like to know is who the hell drives at 55MPH anymore?????? Catch me under 75, and somethings wrong. But now that I know, I'm not too unhappy with an average of 27-28MPG's @ 75-85MPH.

 

Around here lots of people. Most roads are posted 55 Our Interstates are only posted at 70.

 

Cruise set at 75 on a long trip get's 27.1. Back and forth to work get's 25 to 26 depending on TIB....[Time In Boost]

 

No **** right. I only get like mid 20's at best. But I rarely cruise under 80.

 

28.5 at 68mph. I only see "great mileage" on open road intervals, but real life driving combines an element of off highway. Regardless, I have never, ever seen anything over 32mpg under any circumstance, but the vehicle performs flawlessly. My son has seen those "great mileage numbers" of 40-42mpg, but that's with a 2.2 Cobalt XFE (Extra Fuel Economy).