My upgrade to my 04 HCH CVT AT-PZEV was about a tank ago.

My tank is now about 62.4 MPG and may be the same or perhaps 1 MPG better than I would expect considering the driving conditions.

I'm hoping to collect everyone's experience here in one thread.
This way we can see if there is a clear trend.

Did your MPG change?

 

No change, and I'm about 2000 miles into the upgrade.....

 

nope-
mileage got better- but that was because it was summer and it got warm here. its down now with the onset of winter. ugh
and my tank guage still reads about 2% higher than manual calculations as well.

 

No change. About 4500 miles ago.

 

I found that it has helped me by about 2-3 MPGs. (from around 52 to 54-55) The main thing I noticed is that the assist seems to be more "generous" in highway driving situations. For example, I usually practice a technique where I drive at around 60-65-mph/60-65mpg on the flats, then when I go over hills on the freeway, DWL at 40mpg (just short of where assist kicks in), followed by coasting down the backside with the meter pegged. For longer or steeper hills, or if I know I'll be able to use regen soon, I push in just a bit more, still at 40mpg, so that assist kicks in to help out without using any more fuel. I now get a MUCH stronger assist than I used to in this situation, which keeps me from losing as much speed.

However, for driving up the long,slow hill-climb to my house, the assist seems to be about the same (the car switches over from assist to "force charging" at the same place as before).

 

No change in mine after 2000 miles or so. However, bringing it to the dealer did affect my mpg for that tank - I took it in at 49 and got it back at 45. I guess they drove it around a bit :-)

 

That's happened to me, too. My theory is that they leave the car idling for a while when the do whatever it is they do. Otherwise, I would have spotted my beautiful blue car driving around the dealership.

 

4200 miles post-recall and the change has been in style and technique, even season, but little in the way of the software so far as I can tell.

I'm curious though to test this all tomorrow - I'm driving about 500 miles into the mountains north of Atlanta all on interstate. It's the exact same trip I made in early June, pre-recall and pre-break-in and pre-knowinghowtodrivethe****thing, but since I'll be sticking to cruise at around 60 MPH, just as before, I'll get the shot to see how much the car has improved over time and mileage since the driving will be the static.

 

My FE History (average for June thru September):

Summer 2003: 44.61
Summer 2004: 46.60
Summer 2005 (before upgrade): 47.04
Summer 2005 (after upgrade): 50.29

I got the upgrade in August. So I got ~ 3 MPG bump.