I believe there is a point where any possible MPG advantage of Eco mode is lost....
This would include trailer pulling & hilly terrain where running slighty higher RPM's and maintaining gears longer is desirable.
Lugging an engine is never good, although I doubt Toyota would allow this to happen,
Eco mode sure <at times> seems like it is.
If you have to slam the accelerator in Eco to maintain speed then I doubt there is much MPG advantage.
I ran Eco for the first 2 tanks......since then I've ran Sport mode almost exclusively. It's just so much more fun to drive.
I've gotten around 30.8 MPG (calculated) in Sport mode several times......can't complain about that!
2013 Toyota RAV4 XLE AWD - Barcelona Red
2011 Hyundai Tucson GLS AWD - Silver
2014 BMW K1600 GTL Exclusive