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.
If it helps, I have an older Prius and I get about 50mpg using the odometer on the car and the gas meter at the pump. It’s not consistent every fill up because it uses a bladder instead of a rank, so this us averaged over multiple fillups. Sometimes I calculate 64, sometimes 45, and sometimes 50 on the nose. My driving patterns are very predictable, going to and from work 2x/week and some shopping.
I’ve had the car for 10 years now and I’ve consistently gotten about 50, sometimes closer to 45 if winter is particularly nasty.
And this is a regular Prius, not a plugin. The numbers are about what Toyota advertises, if not a little better. I only calculate it because I’m curious, and at this point it’s a complete waste of time.
Note that winter-blend fuel has 10% or less energy in it. Summer-blend fuel has the most energy. And then E15 has less energy, depending on the current market of Ethanol vs Gasoline, you’ll get a little bit more or less energy out per gallon of gasoline.
The variance is expected. No two gallons of gasoline is exactly the same, there’s many blends in the USA and the blends change season-to-season, location-to-location, and even as the laws shift (0% Ethanol decades ago, 10% typically today, and a smooth blend up and down from there depending on what the gas stations decide).