09 Cobalt (LAP motor) - XFE Tuning differences discussion

[DarkNorth Tuning]

Good day lads,
My name is James and I acquired this 2009 Cobalt 2.2 LS sedan auto about 5 months ago for my girlfriend to use.
I became very very interested in learning this platform as tuning is my passion once I realized it was supported and well-defined by HPTuners.

Unfortunately the LAP "community" isn't as close-knit as my mastered platform of CCW Honda motors, and as such I decided to make a post to perhaps bring more people together in search of answers.

During a long afternoon I came across a post by Car and Driver describing a special version of the LS Cobalt called the XFE, I became very interested in this unit after reading of a revised engine calibration allowing extra fuel economy to be squeezed out of an already quite efficient motor.
As my province does not require exhaust emissions checks, I fabricated a stock diameter flow-through downpipe in place of the quite restrictive catalytic converter system in search of better fuel economy and torque.

I made a thread on the Facebook group and was able to get two people to send me their stock calibrations off of 09 XFE 5MT cars.
On one calibration I noticed not much change, but on the latter (provided by a celebrated tuner, although a stock file) I found differences in the fuel section - So I got to research, and there are two different injectors offered on the 09 Cobalt 2.2 (these are their part numbers - 12625029 vs. 12582219).
Trying to research flow-rates of these two injectors has proven difficult, only being able to find what the "stock" injector flows (24 lb/hr, 3 g/s, 250 cc).

Does anyone understand why there would be such a difference between these calibrations?
Cobalt_orig.hpt
2009 cobalt 2.2 stock tune.hpt
2009 Cobalt 2.2 Auto.hpt

Cobalt_orig is the file in question with different injector data
2009 Cobalt stock tune is an XFE comparison file
and 2009 Cobalt 2.2 Auto is our vehicle (Canadian model non XFE w/ 4T45E)

[cadillactech]

Comparing the calibrations, I don't see much difference. Fuel injectors are obviously different but not by much. Couple small other things that aren't enough to impact much.

I think most or all of the MPG gain in the XFE is from the manual trans(less parasitic power loss), taller gearing and I bet most came from the low rolling resistance tires.

I know car and driver says a fuel sipping calibration but I don't see it unless there are other tables we are missing.

[DarkNorth Tuning]

Thanks, do you know why there is a difference in the fuel injectors? I would like to know if there's any benefits to these other injectors.

[cadillactech]

Thanks, do you know why there is a difference in the fuel injectors? I would like to know if there's any benefits to these other injectors.

The flow rate isn't much different but maybe spray pattern?