I've been on the 401 & 417 in Ontario Canada between Ottawa and Toronto, going about 1800 km ever couple of weeks the last 4 months. I've driven it like a speed demon (well okay, the I2 can get to speed but maintaining it is a different issue), and granny cautious..
My best drive so far has been the following:
Keeping the car at 112 km/h (70 mph)
Turning Eco off
Using Cruise Control as often as possible!
2 small grill blocks on right and left of the front plates
Obtained 4.8L (49.3 km, got as high as 49.7 but idling at light killed it so I snapped this one before it dropped further) in 4 hours 8 minutes - 440 km (273 miles). I also want to retry this for winter with all 3 grill blocks in place, I suspect I should be able to hit 51 mpg easily.
However, once I mixed Toronto traffic driving in there to the next fill up I was back up to 5.0L on the MID, at pump calculations it was 5.062 L.
Also some interesting notes & observations:
1) Eco On driving tended to put the MID on the more optimistic side and fill ups on 1/2 - 1/4 empty tanks produced the worst at pump and MID calculations off by as much as 1 L/100km. While less than 1/4 tank fill ups didn't matter if I got it down to range 0 or not produced a 0.8 L/100km difference
2) Echo off driving tended to be closer to the mid, but 3/4 - 1/2 empty tank fill up produces the worst numbers with as much as 0.5 L/100km difference (rounding?)
3) There's a very interesting power curve that occurs at 95 km & 112 km, they are identical in fuel use when I map out the data from the OBD-II. I'm not sure if anyone else has noticed this.
4) Paddle shifters on the EX is fun!
drop it down one when you want to overtake a car and give it some gas.. The fuel use interestingly is slightly better than leaving it in gear, I haven't figured this one out yet.
5) Engine breaking does not generate more regen to charge the battery!
6) While city driving / cruising shift up (if you aren't in 7 already), this seems to save me a but of gas on the MID and seems confirmed on the OBD-II.
7) To ensure consistent fill ups I used 3 fingers from the front of the nozzle and inserted to that point, filled up until it "clicked".
8 ) Stock tires and PSI used, I wanted a less bumpy ride..
Note: I wasn't able to remove the geo-tagging my cell does for the photos so I didn't post it up. You'll just have to take my word for it.