Reset the AVG MPG a couple days ago and haven't really put my foot into and doing ONLY city driving I'm averaging about 18 MPG in town. That's about the same as what it was before the upgrade.

 

See thats what I'm talking about, 18-21 myself on regular driving. When I put my foot in it.... 12-15..... at the track I saw it go as low as 9MPG! NO BS!

I don't like the 18-21 in city.

 

No tune, but I have a (very) long term average of 24.
Mostly all interstate. Mostly level.
Do the math.

 

they must be slipping me the crap gas I average 23-25 I went 60 today just to see what it was like reminded me of covered wagons When I added a 1/4 tank of 101 octane it went off the zoom meter and got 26 racing around only time out of boost was when stopping. My car only got 27 before the stg-1 and was alot slower.

 

Since upgrade i'm getting 20 mpg , 2 less than before. Lots of city plus stop and GOOOOOO traffic.

But i'm ok with that. Guys getting 25-30 mpg with the stage kit .

Maybe if you by-pass the turbo .

 

I noticed from the dash photo that the tach is reading just over 1500rpm @ 50mph. My new 2010 ss 5spd is spinning 2000rpm @ that speed. This may be the answer of the different mpg's. BTW, this is my first post. I just traded a 2008 HHR LS for a SS with the performance package......WOW what jump!!!

 

There were a few different final drive ratios available for the LT's...... could be the same for the SS and that would explain some MPG variation...... Of course location, altitude and temp ranges will cause some as well.

 

Are the final/total ratios the same on the manual 5th gear and the auto top gear with the converter locked up?

 

Answered my own question, looks like the auto has taller gearing. that really helps mpg when cruising.
Great forum,lots of info.

 

I see 21+ in the winter cold using remote start and in the summer I see 23-24 MPG summer in town. I have one short blast for 3 miles on the freeway and I hammer it on the on ramps.

Now regular highway I see 31-32 MPG. Note I am not playing the reset game at every take. I let this go over several weeks and a refill each week. If you play with is you can fudge the numbers if you like.

The fact is the a GM engineer has confirmed that the GMTU will increase MPG 1-2 MPG as they have done the same in testing.

Note the largest gains in MPG with the Turbo engine is letting off the gas. Every time you are off gas on the Direct Injection engine no fuel feeds the engine. Coasting in neutral does not shut the gas off. You need to remain in gear and coast up to lights etc. This will make major gains in MPG.

The turbo upgrade with higher boost will move the car to a higher speed faster and you will get off the gas sooner. This is how the GM engineer explained may there is an increase.