The Cobalt can still do it
 

20 mile trip 50 foot elevation gain, not bad at 112k

Wow great work!

Wow, impressive! What driving style do you find works best for the car? Max speed?

Slower the better, top speed 45, acceleration through careful up shifting (no throttle) when possible eoc to stops. EOC through roundabouts
Roundabouts help FE greatly when empty and are worse than a light when busy :(

This car hates closely spaced stops

Nice work! The 2.2 Ecotec can return amazing mileage with just a little work... I have to work hard to ever get less than 30mpg around home, even when not hypermiling...

Oh the joys of having a manual. :D My autotragic Civic was limited to one 60 mpg trip on the highway....with a tailwind...55 mph max...never to be repeated lol.

I hear ya on the roundabouts though, my college campus is filled with them and they can either be good or one royal PITA.

I can't match your numbers, my XFE average speed is almost always 47 mph. Current tank I'm about 250 miles into with 43.7 mpg indicated, 263,500 miles. Rust is taking it's toll, rocker panels getting holes and had to replace some fuel line a few weeks ago.

My best 3 tank is 45 mpg. Going to switch to E0 for the next 3 tanks to see if I can beat that. Had a fueling issue I just sorted out after replacing plugs, coils, fuel injectors and O2 sensor. Leaking evap purge valve so I disconnected it. 30 mpg last tank to 42-3 this tank. Compression is still good at 192 to 205.

Too fast, my average was likely close to 25mph despite peaks around 45,
I took the shorter city/country route between towns rather than the highway

Tank average dropped into the 50’s after a bunch of short trips during cool weather from and to work. But was still good.

If I had the time and the correct route I could no doubt pull high 50’s over a tank but since I don’t my average from low 40’s to low 50’s is what I have to settle for.

It was refreshing to see that when I actually tried to get decent FE the car still could, although conditions were as close to ideal as I’ll likely ever see on a city street.

Also goes to show that if I lived further from work my fuel economy would likely be much higher, despite the fact I would have to burn more fuel over the distance

When I pulse and glide, I average around 47mph (40/55), but the roads are usually fairly flat as I hypermile... if IATs are between 100 and 110F I can usually average 50+mpg if I try...

That's impressive.
Did you start with a warmed up engine?
What is the % of eoc on those 20 miles?