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.
My overall miles per gallon was 85mpg including electricity.
The 53mpg is within other tests (ex: consumer reports), and is within expectations.
On the contrary. I don't trust Toyotas EV efficiency figure of 3.2mi/kwh because I'm measuring 2.2mi/kwh from the wall.
Are YOU measuring the electrical output from the wall correctly? The cars battery has a figure but it's after the efficiency losses in the cable, heater and other such figures. My calculation includes all the losses except voltage sag in wires (1.5% estimate)
I'm calculating money I was charged by my electricity company actually during charging hours versus miles I actually drove. (The amount of electricity my house uses at that time of night is small and ignorable.) I'm trusting the milometer, but I think that's reasonable. It isn't claiming it's further to work than my previous car did!
In any case, it was almost five times as expensive on petrol as it is on electricity in my usage, and even if you adjusted the figures slightly it wouldn't make a difference. And the pure electric car is so much more fun to drive, with so much more oomph than any other car I ever drove. I love it.
I still think it's weird that you're not calculating your own gas efficiency. Toyota have a vested interest in you thinking they're doing a great job of that. I don't know why you're trusting their figures for gas but you're supremely skeptical about their figures for electricity. Why would they be so inconsistently honest with you, and why are you so inconsistently skeptical?