At the end of the day, I believe folks' dissatisfaction with the HiHy fuel efficiency is primarily due to a mismatch between reality and expectations. This issue is particularly exacerbated by the "have-your-cake-&-eat-it-too" approach by providing more HP in addition to increased fuel efficiency.

The EPA estimates for the AWD HiHy is 27-31 mpg. The reality is about 25 mpg for most folks. If we split the EPA estimates down the middle and say "overall" number of 29 mpg, the difference amounts to about 16%. This is discrepancy between EPA estimates and reality is typical for all types of vehicles, not just the HiHy.

HiHy owners can exceed 25 mpg, but it takes "work", and that's another reality that doesn't meet expectations for many people. The "strings attached with footnotes" can be a bit irritating for first-time hybrid owners, such as myself. My first tank was about 24 mpg. But, after some "work", my FE numbers exceed 27 mpg. My last 8 tanks all exceeded 27 mpg.

What I've found is that "just changing your driving style" isn't enough. It's just not realistic to drive 55 miles per hour on the freeway. What I've had to do is change my driving routes to put me in driving environments where it is more natural to drive more slowly and with less acceleration. So, for example, instead of driving mostly on the freeway for my work commute, I drive mostly on the expressway, where the speed limit is 50 miles per hour. Also to compensate for the potential degradation in acceleration, I use 91 octane, which helps maintain equivalent acceleration even though I'm "lighter" on the accelerator.

The second adjustment is finding a compromise between "working" on the FE and just enjoying driving the HiHy like any "regular" car. What works for me with this regard is to apply light acceleration/low-moderate top speeds approach during the weekdays, and driving normally on the weekends.

At the end of the day, for all the HiHy owners out there that are getting <25 mpg and feel dissatisfied, try making the change to your driving style and driving routes, and you'll find your overall happiness with the vehicle much higher. I know that knot of annoyance in your stomach. I had that too. But after making the appropriate adjustments to operate the vehicle in its "zone" of FE happiness, at least for my work commute, I'm a pretty happy camper...