I'm not really anticipating being a car buyer for another half decade, but the #1 thing I want to judge the industry by & see progressing is MPGe (or kWh per 100km elsewhere). How efficient is your vehicle? Leaving everyone to go figure out efficiency obfuscates what should be a defining characteristics of these offerings!
"MPGe" is an odd measure and probably doesn't actually measure what people think it does. Miles (or km) per kWh (or 100 kWh, but really that's just multiplying by 100) is going to be a better measure. When I think of "MPGe", my incorrect intuition is that it's factoring in the cost of gas and the cost of electricity to create a cost per mile that results in an "MPGe" relative to gas prices. ie, a 60 MPGe car would co…
Miles per dollar would be extremely region specific. And temporally specific; it'd change as prices wax and wane. I don't see how such a MP$e would in practice work.
My understanding is much of the world does kWh/100KM, which by virtue of the constant gives a reasonable straight number. Tesla for example has a page called European Union Energy Label, where we get figures like: Model 3 Rear-Wheel Drive, 13,2 kWh/100 km. It's perceived as more human friendly I guess than .132kWh/KM.
It definitely does seem like having the two units - either 1 gallon or 33.7kWh EPA - makes it really hard for consumers to understand the relative merits of their vehicles.