cross-posted from: https://lemmy.world/post/22892955
The Prius Prime is a dual fuel vehicle, able to run 100% on Electric, or 100% on gasoline, or a computerized blend in-between. This presents me a great opportunity to be able to do a direct comparison with the same car of an EV engine vs an ICE engine.
Toyota computer claims 3.2mi-per-kwhr.
Kill-a-watt (https://en.wikipedia.org/wiki/Kill_A_Watt) claims 2.2mi-per-kwhr.
Additional 1.5% losses should be assumed in the wires if you wish. (120V drops down to 118V during charging, meaning 2V of the energy was lost due to the resistance of my home's wires).
Level 1 charger at home (known to be less efficient).
Toyota computer claims 53miles-per-gallon (American Gallon).
I have not independently verified the gallon usage of my car.
295 miles driven total, sometimes EV, sometimes Gasoline, sometimes both.
30F to 40F (-1C to 4.5C) in my area this past week.
Winter-blend fuel.
12.5miles per $electricity-dollar (17.1c / kw-hr home charging costs)
17.1 miles per $gasoline-dollar ($3.10 per gallon last fillup).
If anyone has questions about my tests. The main takeaway is that L1 charging is so low in efficiency that gasoline in my area is cheaper than electricity. Obviously the price of gasoline and electricity varies significantly area-to-area, so feel free to use my numbers to calculate / simulate the costs in your area.
There is also substantial losses of efficiency due to cold weather, that is well acknowledged by the EV community. The Prius Prime (and most other EVs) will turn on a heater to keep the battery conditioned in the winter, spending precious electricity on battery-conditioning rather than miles. Gasoline engines do not have this problem and remain as efficient in the winter.
I originally wrote this post for /c/cars, but I feel like EVs come up often enough here on /c/technology that maybe you all would be interested in my tests as well.
Thanks for this. Are you planning to take more measurements during a warm season? It would be interesting to see how close the electric system comes to petrol in more favourable conditions/climates.
Of course! I plan to keep this car for around a decade, so there's plenty of opportunity next year to experiment again.
Between the heater during charge + the heater during driving (!!!), we are getting hit twice by the cold weather efficiency demons.
Today was 50F (10C) and I'm estimating closer to 3mi/kw-hr.
Or in other words, warmer weather is close to +25% more range and efficiency compared to last week's cold weather test.
Note that this number is very preliminary (ie: reliant upon Toyota's battery measurements) and I'm currently recharging my car with the Kill-a-watt to verify my initial estimates. I've also got a work meeting tomorrow morning, but I'll try to write down the results of today's warmer weather test and report back to you.
Alternatively, if I forget to write down the Kill-a-watt results tomorrow morning, I'll just repeat the test again on Wednesday or something. It should be warm weather all this week.
2.87mi/kwhr is the final number for 50F test.
That's +38% range. Or conversely, a 28% drop during freezing conditions. Or 72% efficiency near freezing compared to 50F.
Measured from Kill a Watt and therefore still a L1 charger that may have other inefficiencies.
Huge differences between 50F and 30F. Very curious indeed
L2 charger at work returned 3.4mi/kwhr !!!!!
L2 charging at 50F (and below) is clearly way more efficient than L1 charging.
With this, I can safely say that L1 chargers should be avoided if possible.