MPG with the GMPP Turbo Upgrade
03-17-2011, 05:58 AM
#21
Senior Member
Thread Starter
Join Date: 08-20-2006
Location: Hillsdale, Michigan
Posts: 21,640
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.
03-17-2011, 06:10 AM
#22
Senior Member
Join Date: 05-13-2008
Location: Knoxville, TN
Posts: 2,075
I don't like the 18-21 in city.
03-17-2011, 07:36 PM
#24
Premium Member
Join Date: 10-09-2010
Location: Tacoma
Posts: 14,420
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.
03-17-2011, 07:51 PM
#25
Senior Member
Join Date: 06-26-2008
Location: N.W. Burbs Chicago
Posts: 4,152
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 .
But i'm ok with that.
Guys getting 25-30 mpg with the stage kit . Maybe if you by-pass the turbo .
03-19-2011, 01:01 PM
#26
Member
Join Date: 03-18-2011
Location: Western New York, Lancaster
Posts: 54
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!!!
03-19-2011, 01:44 PM
#27
Senior Member
Join Date: 03-06-2010
Location: Ohio
Posts: 6,869
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.
03-19-2011, 04:08 PM
#30
Senior Member
Join Date: 07-05-2008
Location: Akron Ohio
Posts: 5,464
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.
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.
