Well this is a forum so I'm glad to give my opinion and Clarity PHEV experience. (I've no connection to the manufacturer or its advertising). First of all my experience with a new Clarity has only been about 9 weeks.
In that time I've learned that it's electric range varies a lot with ambient temperature. In the warmer weeks, the AC was on and I got from 2.5 to 3.0 miles/KWH (42.5 to 51 miles per full battery charge). In the colder weeks the cab heater ran under "comfort control" (I didn't use any other available aux heat device) and I got from 2.1 to 2.6 miles/KWH (36 to 44 miles per full battery charge).
I'm retired, don't have that many miles to drive, so can try to drive my Clarity like a total electric car. The charge in KWH that the car takes-in every night is measured. From this and the monthly electric bill I know how much battery charging costs. I'm even careful about not pressing the accelerator when driving downhill so that electric motor isn't powered needlessly. The way one presses the accelerator in the EV mode will of course affect battery use efficiency. I know if I press the accelerator beyond the "click point" (75%) that the car will automatically be thrown into its HV mode and that that mode will remain 'on' for at least 10 minutes, unless the car is stopped and re-started in the EV mode. If I'm in a rush and drive it like a gas engine car, even if I don't press down to the "click point", the battery use will be higher.
Also, it seems to me that "cab heating" takes much more energy (battery KWH) than "cab cooling". So that is what buyers in the Fall experience most shockingly. I do wish Honda would make an effort to advise Clarity customers of its variable efficiency, especially to Fall buyers. Here's the way I think. IF they advertise the car at an average of: 47 miles/(full battery) charge and IF you can get 58 miles/charge as a maximum, then the math might be like:
(58 + x)/2 = 47 => where x = 36 miles/charge (the minimum range Clarity gets)
For a portion (winter) of the year we can expect to be at this 'low end' efficiency value. Of course, I must wait until next year to see if all this pans out as expected :>)