[jauntywundrkind]

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!

[russell_h]

Is there really much room for improvement on efficiency without moving to very different form-factors?

I would have figured that rolling resistance and air resistance account for the huge majority of the energy usage without much room for improvement over eg a Model 3, unless you make it look like an F1 car or give it solid tires or something.

[jauntywundrkind]

Right now some of the Model 3s are leaders of the pack, at 130+ MPGe. I expect some gains are possible, but yeah, not a ton in the current incarnation of cars.

But it's something I feel like should be at forefront of mind. Competitors should be trying to get to top of pack, but very few are >120 MPGe.

Also it should be more obvious that big E-SUVs, even if they have big range, are actually joule hogs. Seeing a 70 MPGe should be a turn off.

And if we do change architectures? The Aptera has been talking about a 337 MPGe system for a while. It's an incredibly impressive idea, but only if people have the context to understand relative efficiency versus other EVs. We need to be building the base knowledge to evaluate, to appreciate wins, and to keep car makers from regressing.

[Sohcahtoa82]

"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 cost half as much per mile as a 30 MPGe car.

But as mentioned, this is incorrect. "MPGe" is based purely on some idea of how much energy a gallon of gas has in kWh, and miles/kWh is used to calculate that.

The result is that a 60 MPGe car could cost just as much, if not more, to drive than a 30 MPG ICE if gas prices are low while electricity costs are high.

[jauntywundrkind]

It's called miles per gallon equivalent. To me, the name is plenty clear & I don't see how one would be confused. Yes one needs to understand the price of those fuels to figure it out.

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.

[AnthonyMouse]

Most people who don't drive an abnormally large number of miles have never much cared about fuel economy because it's a relatively small part of the cost of owning a car. At $3/gallon and 12,000 miles a year, the difference between 20MPG and 40MPG is $75/month, and when gas was $1.50 it was half that.

This is even less of a concern with electric vehicles, both because any electric vehicle is already more environmentally friendly (you can feasibly charge with 100% renewable energy regardless of MPGe), and because the energy cost will always be lower than it was for gasoline vehicles, which leaves even less monetary value on the table for possible gains from efficiency improvements.

So almost nobody is going to care about that unless we end up in a world where electricity prices are dramatically higher than they are now.

[Twistyfiasco]

Pretty sure that's a feature.

[reducesuffering]

Agree. the 26.5 kWh for 100 miles at California electric prices (0.40$/kWh) is not great compared to hybrids. That's the same price it costs to run a Prius at gasoline prices of $4/gallon.