I was consistantly getting 27.5 MPG on my way yo work and back. Mostly 45-60 mph. When I got the Stage 1 upgrade I didn't see any noticable difference in gas mileage. Now, two months later I'm seeing 22 mpg average. The only difference is now that it's hotter I've been running the AC all the time. Can't believe the AC would kill the MPG that much. I've run three or four tank fulls from different stations with the same results. Seems like the performance is unchanged. No codes. Any body else have simular situation?

 

I would think the AC running and the hotter weather could be most of that difference...... I don't have an SS, just speaking in general.

 

Me thinks that running the A/C a lot, would make the 5mpg drop. Have'nt ever really checked, but all my cars before seemed to get worst mileage when I ran the A/C a lot. "Moon"

 

I haven't noticed that much but I would say in the city w/o A/C for me on my SS is 22mpg. Just as the sticker said. With the A/C on, its 19mpg. Sometimes 20mpg.

Recently, in the rain with the A/C (only like the 2nd time in the rain) I found myself enjoying the hell out of the wheel spin... so I'm getting like 17.8mpg. But having fun with it.

Mine being a 2010 SS with a 5speed

 

mine has dropped to 16.7 mpg around on the hwy about 19, i have the 2.4 2lt did not buy it for gas mileage runs great next week will have a dealer check the computor prog.

 

I've lost about 3mpg's with the A/C being run all the time.

 

Mine has taken a small hit to 22 mixed. A/C is the culprit IMO.

JIm

 

Ethanol is less volumetrically efficient, and it might be added in summer where you are.

 

I did a 200 mile ride up/down/up secondary roads in New Hampshire yesterday with the AC on the whole way.
It averaged 32.3 overall, starting from a local tank-fill.

My results are slightly skewed because I roll up to and over hills and hurtle down the other side to get momentum up the next.
Very efficient when possible and yesterday's ride was probably >75% with no traffic following.
I only averaged about 35 MPH because there were a few miles of dirt road here & there and some stopping to refer to the street index.
Most of the driving was between 45 and 55 though.

I'm totally surprised that it's comperable to what it would have been without the AC.
In the old days with a V8 I'd turn on the AC and watch the gas gauge move.

OTOH - With the AC on I see 0 MPG when I floor it and aggressive acceleration causes way lower MPG than with the AC off.

YMMV

 

I know in St. Louis, we have a "summer formula" gas. Could it be the culprit?