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Dave - current formula 1 engines are 51% efficient - Mazda are developing an engine that is 56% efficient, Toyota have already developed an engine that is 36% efficient.

There is no such thing as a zero emissions power grid - you will not find a single credible source that supports that view.

45% of the Western US grid is powered by fossil fuel.

I'll remind you that the main constituent of natural gas is methane and that one mole of methane converts to one mole of carbon dioxide during the combustion process. I'll also remind you that methane is one of the more nasty greenhouse gasses.

Furthermore, the Model X at nearly 5000lbs is a huge consumer of natural resources.
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Self discharge is a fair point. The EPA tests do include some self-discharge, however they likely underestimate it especially for larger batteries.

The EPA test is to fully charge the battery, allow the car to sit overnight, fully deplete the battery the following day by driving the road cycle, then recharge with the manufacture's charger and measure the energy consumed. Thus the measured miles include ~24 hours of discharge in the case of a shorter range car, or more like ~36 hours of self discharge on a model 3 (given the 12 hours needed from zero with the supplied charger). On a shorter range car (ie 500e) this procedure in theory accounts for ~43% of the self-discharge based on 13,400 miles per year. If we accept self discharge 1% per day (which I agree seems standard and is in the Model 3 owners manual) that means there are 177 miles worth of self-discharge per year not accounted for, and this in turn increases the calculated carbon intensity by 1.3%.

On a longer range car like the Model 3 1% per day has a much larger impact- the EPA's test would only account for 20% of the self-discharge you'd expect annually, leaving 862 miles or 6.4% annually that I did not account for in my calculations. Self-discharge is fastest when a battery has just been charged so the EPA test might capture slightly more of the effect than I'm calculating here, but I agree it's certainly not capturing all of it.

Unlike most battery types Lithium Ion appear to have stable self-discharge over their lifespan, however temperature does effect the absolute number (with higher temperatures increasing self discharge). Parasitics from the battery cooling system and drain from the electronics/ cell connection (over the air software updates, etc) are wildcards, and I agree both could increase discharge rates very significantly.

As a side note I've been on an international trip for the last week and my Model 3 is sitting idle in the garage unplugged. Starting from a 65% charge state it's reporting that I appear to be losing 2 miles per day or roughly 5% per year. So I'd suggest between 5 and 7% looks reasonable, which puts the boggy for an equivalent ICE at somewhere between 45 MPG and 68 MPG based on the national grid depending on net battery intensity and the car's lifespan. But your 1.5L CVT Civic gets 36 MPG combined by the same test standards, so the Model 3 is 25% more efficient?

While we're sharpening our pencils let's include the anticipated 10% reduction in carbon intensity of grid electricity over your hypothetical 10 year lifespan, both nationally and worldwide.



Even the best EVs on the California grid are very far from where we need to get to. And I agree that there is no one size fits all- grandma who drives 3,000 miles per year should buy your 2.5L gasoline engine car even if she doesn't live on the east coast. Especially if she's considering an I-Pace as an electric alternative. That said for the average American we are now past the point where a standard ICE car can compete on a life cycle emissions basis with a good EV, as an accurate evaluation of best in class available alternatives shows (ie your Civic 1.5 CVT vs the Model 3). For the average Californian there is clearly no comparison. And while ICE efficiency will and must improve the grid electricity mix and battery manufacturing are only likely to extend good EV's lead. Your statement that "From manufacturing to recycling an electric midsize sedan pollutes more CO2 than a 2.5l gasoline car" was counter to that. It implied that most people would be better off from a carbon footprint perspective buying a fairly average ICE, and that's simply false.

Last time I put a car on the chassis dyno the transmission and diffs ate about 80hp, so there goes the efficiency. Also, ICE efficiency depends heavily on rpm and delta rpm. With steady state fixed rpm continuous load you can tune for max efficiency, real world variability not so much. The fact that all ICEs have a torque curve rather than a torque straight line tells you that. F1 engines are tuned at WOT, not super useful taking the kids to school.
The complexities of trying to squeeze a few percent more efficiency out of an ICE such as variable valve timing, variable compression, Miller cycle, auto stop/start, etc. just create the need for more parts, more service and less reliability. If you want great gas mileage from an ICE its pretty simple: a light weight car with a tiny engine tuned for low rpm operation. Even then you will run into a wall at 45mpg or so. Don’t plan on drag racing a Tesla either.

Comparing laptop and cell phones to EV batteries is not apples to apples - cell phones and laptops don’t thermally or charge manage their LiON batteries so their life spans are radically different. You can greatly enhance LiON battery longevity with thermal and charge management - don’t use your cell battery experience and extrapolate that to EV’s even if they are the same physical cell - the operating environments are radically different and the results are different!

Doesn’t overheat anymore

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