Well, I have to say that adding an MPGuino as FE instrumentation has made a VERY noticeable difference in my overall FE!
I added a few aero mods back in July, pre-'guino. Grill block, one wheel cover, one skirt. The FE of the two tanks (~1000 miles) after the mods were nearly the same as the two tanks before the mods (50.5mpg after vs 50.9mpg before). Adding the 'guino, my average has jumped to 54.9mpg over the last 4 tanks (about 1,900 miles)!! And that even includes half a tank with most of the aero mods removed (only had one rear wheel skirt).
In summary:
| Description | Date Range | 'guino | aero mods | Miles | Gals | MPG |
| Last 4 tanks | Mid-Aug to Mid-Sep '10 | Yes | Yes* | 1,918.7 | 34.93 | 54.9 |
| Pre-'guino 4 tanks | Mid-June to Beg-Aug '10 | No | For last 2 tanks | 1,818.5 | 35.85 | 50.7 |
| Prev Best 4 consecutive tanks | Mid-Aug to Beg-Oct '09 | No | No | 1,904.3 | 36.16 | 52.7 |
*Had grill block, one wheel cover, and one rear skirt for all but half of one tank
To me, it's clear that the immediate feedback available via the 'guino display is significantly more effective than the (few) aero mods I did, based on the tanks before/after the aero mods, vs the tanks before/after the 'guino install.
The 'guino is definitely invaluable for taking the best advantage of any other mods (aero and otherwise). My sincere thanks to those that have made this device possible!!