Josh, thanks for checking in and offering assistance with the suspension!
After a few weeks of practicing driving technique, I've learned that I'm already a pretty economical driver.
i didn't realize any real improvements in mpg with eco driving. Not to say a few of you couldn't put up better numbers in my car but I personally can't. I'm even logging a/f and a few other things with a monitor and my normal driving style seems to be as conservative as I can get, even with utmost concentration.
After that, I ran a few known trips back to back to back with roof rails off. No improvement at all. I guess I should clarify that maybe I'm looking for gains in the wrong way...I commute about 20 miles per day. I can increase my mpg by taking a different rural route which nets me between 10% and 15% better fuel economy. Problem is, that makes my commute 30 miles total and I end up burning more fuel even though my mpg is higher.
I do very few highway trips but I'm sure the mild aero mods I'm planning will help there.
So my quest seems to have moved out of aero and into actual engine efficiency. Sure, going from 42 to 44psi has helped a bit on a full tank. Up next is engine block heater. Then you folks will likely think I'm crazy but I'm going to run a piggyback ecm and lean out the fuel maps, adding water injection to keep detonation at bay. Parts are already piling up.
Could it be that volvo already tuned this thing with an eye toward economy and 21 city stop-n-go is the best I'll ever achieve? Is 2mpg (10%) over epa ratings not as sad as I think it is?