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Well, acording to wikipedia gasoline has an energy density of 46.4 MJ/Kg and LiPo batteries have an energy density of 0.36–0.875 MJ/Kg. So if your electric driv

Well, acording to wikipedia gasoline has an energy density of 46.4 MJ/Kg and LiPo batteries have an energy density of 0.36–0.875 MJ/Kg. So if your electric drivetrain has a 100% efficiency and your gas drivetrain has a 30% efficiency then the gasoline car would be able to do 16 times more work per unit of fuel.

_aavaa_ 3y ago
And yet, electric cars you can by today don’t have 1/16th the range of a gasoline car. So energy density is not enough.
- goodSteveramos 3y ago
  Not enough for what? The energy densities of both LiPo batteries and gasoline are enough to make a passenger vehicle with an acceptable range. For gasoline it is more than enough and for LiPo it’s barely enough.
  - _aavaa_ 3y ago
    Sorry, got cut off. So energy density on it's own is not enough to tell you whether is viable for making a car based on it.
ceejayoz 3y ago
> then the gasoline car would be able to do 16 times more work per unit of fuel OK, so we've got ~300 mile range electric cars. Where are the 5,000 mile range gasoline cars?
- erik_seaberg 3y ago
  A Tesla Model 3 has 1060 pounds of batteries. If you replace those with a 177 gallon gas tank (at 6 lbs/gal) you should be able to go 4,780 miles at 27 MPG. It’s just that nobody wants to give up that much volume (visualize a 6x6x5 cube of gallon milk jugs). I’m not accounting for a gas engine having more heavy parts, that mostly matters in city driving.
  - goodSteveramos 3y ago
    27 MPG is abysmal. The 2024 Prius gets over 50 MPG so it could be closer to a 10,000 mile range.
    - erik_seaberg 3y ago
      I was surprised a Prius does that well beyond the range of its battery. I took a number from https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles after a quick search, though it’s about 20% worse than my aging Hyundai.

_aavaa_ 3y ago

And yet, electric cars you can by today don’t have 1/16th the range of a gasoline car. So energy density is not enough.

goodSteveramos 3y ago
Not enough for what? The energy densities of both LiPo batteries and gasoline are enough to make a passenger vehicle with an acceptable range. For gasoline it is more than enough and for LiPo it’s barely enough.
- _aavaa_ 3y ago
  Sorry, got cut off. So energy density on it's own is not enough to tell you whether is viable for making a car based on it.

ceejayoz 3y ago

> then the gasoline car would be able to do 16 times more work per unit of fuel OK, so we've got ~300 mile range electric cars. Where are the 5,000 mile range gasoline cars?

erik_seaberg 3y ago
A Tesla Model 3 has 1060 pounds of batteries. If you replace those with a 177 gallon gas tank (at 6 lbs/gal) you should be able to go 4,780 miles at 27 MPG. It’s just that nobody wants to give up that much volume (visualize a 6x6x5 cube of gallon milk jugs). I’m not accounting for a gas engine having more heavy parts, that mostly matters in city driving.
- goodSteveramos 3y ago
  27 MPG is abysmal. The 2024 Prius gets over 50 MPG so it could be closer to a 10,000 mile range.
  - erik_seaberg 3y ago
    I was surprised a Prius does that well beyond the range of its battery. I took a number from https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles after a quick search, though it’s about 20% worse than my aging Hyundai.