EPA Ratings - when?

[Freyar]

It comes from the fact that there is 33.7kw of chemical energy in one gallon of gasoline. In a ICE less than a third of that energy is converted into usable mechanical energy. Most of it is lost as waste heat.

Good to know about that. Helps reframe the argument, though if I'm understanding it right, I imagine this law behind waste heat is not really something that comes to customer's minds (as it didn't occur to me either.)

 

[AZFox]

EPA figures need to be on the Monroney sticker, so they'll be available before you can order your Slate FN.

Are we there Close To Production yet?

 

[AZFox]

I'm thinking just a M/kWh would be a better metric and keep it separate from gas.

Better yet, a more intuitive KWh per mile if it's going to change.

TL;DR: Miles-per-unit can be deceptive. Units-per-mile is inherently more intuitive.

Units-per-mile is more informative for comparison than -per-unit because it measures the amount of energy or resource used per mile, which provides a direct measure of efficiency. This allows for easier comparison between different vehicles or systems, as it shows how much energy is consumed over a specific distance. For example, miles-per-gallon (MPG) measures how far a vehicle can go on a gallon of fuel, while gallons-per-mile measures how much fuel is used to travel a mile. The latter provides a clearer picture of fuel efficiency and resource consumption.​

 

[EVfun]

MPGe is such a weird metric..
To trust it, I'd have to understand how they came to 1 gallon = 33.7kWh, and I have a suspicion it hasn't been adjusted for improvements to the technology.

I'm thinking just a M/kWh would be a better metric and keep it separate from gas.

I agree that using miles per kilowatt hour makes the most sense. We buy electricity by the kWh, we buy gasoline by the gallon (US). So using M/kWh is looking at it the same way as MPG, just with a different "fuel." If the Slate goes 205 miles on a 63kWh pack then it works out to 3.25 M/kWh.

Since there are about 33.7 kWh of energy in a gallon of gasoline, the energy efficiency is equivalent to a gasoline car getting 109.6 MPG (MPGe). We don't really need that, but it may help people mentally transition.

 

[Shay]

Most of the time ratings aren’t posted until at or near the first delivery of the vehicle. The manufacturer most often tests the vehicles themselves under a prescriptive program. They then submit the results of their testing for certification. The EPA itself rarely actually tests vehicles themselves unless there’s a reason to double check what a manufacturer has been saying.

 

[MAUICUDA]

MPGe is such a weird metric..
To trust it, I'd have to understand how they came to 1 gallon = 33.7kWh, and I have a suspicion it hasn't been adjusted for improvements to the technology.


I'm thinking just a M/kWh would be a better metric and keep it separate from gas.

I agree. My 2020 Leaf dashboard shows 4.3 m/kwh. Easiest for me to understand and comprehend.