(OK, first of all, I admit I made a spreadsheet to keep track of actual expenses/mileage etc. for my 2010 Insight. And yeah, I get teased for it.)
So here is my mileage experience so far:
Initially 44.75 all hwy miles driving it home 238 miles in February (Ohio to Indiana). I was 'babying it' and my wife just shook her head at my 60 mph average. (she was in a separate van and MAYBE beat me home by 5 minutes). Anyway, MPG then hung around 50 for several weeks (incrementally better each week, about 1200 miles total) while I was trying to figure out how to get the 'efficiency' bar closer to the '75' mark (rather than 50). Last week on hwy driving (around 60mph ave.) I got 52.9 (on 294 miles). But since that route to work adds about 5 miles each way on a 30 mile travel, it really doesn't save me any time, so I decided this week to cut through Indianapolis, timing lights and trying to keep mph at around 40. Result: not only did I save 50 miles of driving for the week, but my mpg went up dramatically to 58.5 (on 238 miles driven) ! And summer is not even here yet!
I was under the impression that the Insight would do better on hwy since it is rated better (3 mpg difference) but if you can time your lights and keep a fairly steady speed, I guess that's not the case. The key appears to be 'babying' it and getting 'light' on the pedal where possible so as to go from the '50' to around the '70' on the bar. So 40 mph is a pretty sweet spot for my driving! Anyway, I felt compelled to brag as I didn't expect too attain close to that mpg until summer! What a game.
[only modifications are inflating the tires to 40, and blocking most of the grill with the foam pipe wrap (and I must say I think the smooth pipe wrap looks sharp tucked into the grill !)