80% of your gas money goes out the tailpipe
80% of your gas money goes out the tailpipe
Key context: thermodynamics dictates that heat engines waste a lot of energy.
Credit: Karin Kirk
It's even worse when you take a bunch of the small percentage of energy the heat engine successfully turns into motion and then use it to heat up the brake discs.
Being able to recapture kinetic energy into a battery and reuse it later helps overall efficiency a lot.
Plug-in hybrid? Aren't they worse than both, because of the weight of motor and battery?
You also get to use a smaller lighter ICE motor which is augmented by nearly instantaneous electric power. My favorite car was a Prius C which is no sportscar, but feels much zippier than you would expect for getting 50 mpg.
Series plug-in hybrids that can run on battery (Chevy Volt, Honda Clarity, Prius 2024) are IMO better than both. They effectively operate like electric vehicles (regenerative braking and all), and one can drive them for months without burning gas. Their batteries are about five times smaller (~30-50mi range vs full EV's ~250mi range), and thus lighter, and the gasoline engine is usually a small, efficient one (~40ish mpg on gas)
Yes, unless your only metric is fuel consumption or range with a given tank. Then they're pretty strong.
Only 70% going out the tailpipe.
I think the 80% number is outdated (although most of the energy is still wasted)
F1 engines achieve a peak thermal efficiency above 50 percent, significantly higher than a modern passenger car's 35 percent thermal efficiency - https://www.motor1.com/news/655596/video-how-f1-engines-make-1000hp/
So more like 65% goes out the tailpipe...
If your rolling coal, you are literally pumping unused diesel fuel out the car. You're efficiency is absolute dog shit.
Well-To-Wheel energy efficiency:
Gasoline: ~20%
Diesel: ~30%
H Fuel Cell: ~25%
BEV (fossil power): ~20%*
BEV (renewable): ~55%**BEV is highly dependent on energy source. Anwhere from ~20% WTW from natural gas power generation to 75% from roof-mounted solar.
Keep in mind this is a summary of a summary of a summary.
Sources:
- https://www.researchgate.net/publication/344860096_Comparison_of_the_Overall_Energy_Efficiency_for_Internal_Combustion_Engine_Vehicles_and_Electric_Vehicles
- https://c2e2.unepccc.org/wp-content/uploads/sites/3/2019/09/analysis-of-hydrogen-fuel-cell-and-battery.pdf
- https://yaleclimateconnections.org/2022/08/electrifying-transportation-reduces-emissions-and-saves-massive-amounts-of-energy/
Technically solar panels are only ~20% efficient, but there's also virtually unlimited sun so it doesn't really matter.
Scotland disagrees
All sources i can find, gasoline to wheel is around 15, 16 %. Is this without parasitic etc. losses?
Edit: right, well to wheel.
When people realize that heat is actually energy and not just some free byproduct :o
How much of your EV charging money goes out the power plant smokestack, into the river/cooling tower, or heats up the air around the electrical wiring though?
i’m a proponent of EV’s, even when they charge from fossil powered grids, because of the thermodynamic efficiency gain.
But ragememes, no. Let’s not be like that.
In most places, at most times of day, a lot less.
Why? First, because a lot of electricity is generated using wind, water, solar, and nuclear. Those don't have that problem (ok, nuclear wastes a lot of heat, but really, who cares). The second reason is that power plants that burn stuff tend to be a lot more efficient than internal combustion engines; the best case is combined-cycle gas turbine power plants, which turn over 60% of the energy available into electricity, as compared with a gasoline engine which turns about 20% of the energy in the gas into motion.
So this made me wonder: How do nuclear plants produce the heat? Like, I know they're using nuclear materials to boil water and generate steam to turn turbines, but how is that accomplished? Are the fuel rods just naturally hot (in terms of thermals not just the radiation) or are they running current through them to make them hot enough to boil water? I always assumed the former, but maybe I've been wrong this whole time.
0 - 100% of my electric comes from wind. Which is the real win for ev, we have a path to better.
I've always emphasized that gasoline comes from oil. Electricity comes from oil. Or solar. Or nuclear. Or wind. Or hydro. Or hamsters running on wheels. Lots of sources to choose from!
That depends on the production and distribution of electricity and not so much the EV.
It's impossible to state any number that would be correct for all cases, but I would guess with a great deal of certainty that it's a hell of a lot less than is lost on production and distribution of gasoline.
And even in some crazy home made diesel generator scenario where the power isn't produced and distributed more efficiently than gasoline, the EV is still about four times more efficient in using the energy after it has been produced and distributed.
The meme only mentions the efficiency of the vehicle so it'd be unfair and in bad faith to compare it to to electric infrastructure and assume it also comes from fossil fuels.
How much energy is spent in mining, refining fossil fuels, transporting it and distributing to gas stations? Crunch these numbers before starting to compare it to electric grid.
You can run an EV from coal dependent electricity and you're carbon positive after less than 60k miles compared to a gas car.