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ICE motors have been evolving for over a century now so the improvements will become ever smaller. Despite that slowdown in progress, the energy density advanta

ICE motors have been evolving for over a century now so the improvements will become ever smaller. Despite that slowdown in progress, the energy density advantage of fuel over batteries still vast. Regulation should, in my opinion, be be aggressively pushing towards reducing vehicle size and weight instead of focusing on the fuel. Having a 2 ton car to move a 60kg person from stop light to stop light is just insane

avhon1 6y ago
One of my personal fantasies is that the United States imposes a maximum road speed limit of 45 miles per hour (72 kilometers / hour). As a result, cars get lighter, more efficient, and safer, and trains become more popular and practical means of traveling long distances. 45 miles an hour seems like a reasonable compromise speed. At 65% the common highway speed limit of 70 mph, it's still fast enough to cross most states in a day, to travel between nearby cities in an hour or so, and to do errands in an afternoon. But a car at that speed has only 41% the kinetic energy as at 70 mph, making colisons less lethal, and has similarly less wind resistance, requiring smaller engines and less fuel. Maybe I just think trains are romantic...
- clarry 6y ago
  I'm conflicted on this because I'd like those gains in safety and efficiency. I think it'd also allow us to live with smaller & curvier roads, which I think are romantic and kinda relaxing. (I'm quite bored with the wide straight flats they build; those also ruin the scenery and generate lots of noise) On the other hand, cars have been getting safer and faster and more efficient, roads have been getting wider and safer.. only speed limits haven't been lifted to match. A part of me wants to live the utopia where I can get where I want to be in less than half the time it takes today. That'd make the difference between going to my parents for a coffee after work vs having to reserve a full day (if not a full weekend) for the trip. Trains are not really a solution around here.
  - avhon1 6y ago
    I think speed limits have informally (and unevenly) been rising to match the capabilities of new cars and roads. I visited a new area recently, and was shocked to see that traffic was flowing at 90 mph (!) in a 70 mph zone. I was glad I wasn't driving, because not only is that a greater posted-vs-actual speed difference than I've seen before, but I've never actually driven that fast in my life. I'd have been torn between driving 80 in the right lane and being constantly passed at 10-15mph, or being white-knuckled behind some other vehicle and setting a personal landspeed record.
    - clarry 6y ago
      Maybe they have in some areas. In my case, rural Finland, it's been the same for as long as I remember. Maximum limit is 120 km/h on freeways (and there are practically none of them where I usually drive), elsewhere on bigger inter-city roads it's 100 km/h during summer and 80 km/h during winter. Lesser roads, never more than 80 km/h. And traffic never flows significantly faster than the limit. A few km/h over the limit at most. There are some weirdos who drive much faster and are constantly overtaking others, but relatively few people drive like that. If anything, it seems to me that speeding has become less common over the years as the police have tightened the limit at which they'll fine you.
      - TomMarius 6y ago
        I am from the Czech Republic. Left lane on highway is informally reserved for "going fast", as in 160-200+ km/h. Right lane is around 120-140 km/h. Oficial speed limit is 130 km/h. Regional roads are limited to 90 km/h, but people travel as fast as 160 km/h on the largest ones. Town areas are limited to 50 km/h unless said otherwise and it required automated radars to get drivers to go less than 90 km/h in many towns on major roads. People are basically behaving like it's German autobahn everywhere. Even the informal rules have adjusted - in a major city, you not only respect the right hand rule, but also give right of way to all vehicles on the more major road. The conflict is resolved by blinking headlights. Honda used to be the most popular brand here (90's and first few years of 00's).
    - 6y ago
- jacobush 6y ago
  You could just build better trains, it's going to take state or fed level money to do that anyway. If the trains were better, people would use them. In practice, todays 70 mph is not much different from 45 mph. You can't drive 70 mph nonstop, medium speed is lower.
  - avhon1 6y ago
    Yes, my fantasy is less like "improving Amtrack" and more like "replicate Japan's Shinkansen".
    - ectospheno 6y ago
      Japan is the size of California. Replicating that across all of a larger country such as the United States isn't realistic.
  - 0xffff2 6y ago
    >You can't drive 70 mph nonstop What do you mean by that? If you're covering long distances in the Western US, it's not at all uncommon to be driving 70+ for hours at a time.
_ph_ 6y ago
Having a 2 ton car to move a 60kg person from stop light to stop light is just insane That is solely determined by the energy required. And there is, where the electric car excels. A Tesla uses less than the equivalent of 2l of fuel for 100km or in other units achieves 120mpg. In situations you describe, it fares even better, as 60% of the kinetic energy built up is gained back when braking using the electric motors. So mass is much less a problem with electric cars than with combustion engines, which can't recuperate the kinetic energy.
- avhon1 6y ago
  Electrics are great for low-speed stop-and-go. They're not as good on a highway, though. 0% of the energy spent displacing air at 70mph is recovered.
  - _ph_ 6y ago
    They are still better than any car with a combustion engine at highway speeds. They don't recuperate while driving at constant speed of course, but still they have the greater efficiency of the electric motor vs. the combustion engine. Usually they have better aerodynamics too. But the weight doesn't play a role there, only making the cars physically smaller - less air resistance - would improve the energy consumption at highway speeds.
  - FrojoS 6y ago
    Yes, but weight (which is higher in electric cars) does not influence air resistance. Tesla’s btw have record low air resistance.
- rootusrootus 6y ago
  Regenerative braking is always, always less efficient than just not spending the energy in the first place to speed up. And there are currently more fossil fuel cars on the road with regenerative braking than there are EVs ;-)
  - _ph_ 6y ago
    To use 60% less fuel, the car needs to havee appropriately less mass, so you are talking about 700kg for a 5 seated car with passengers. If you are talking about fossil fuel cars with regenerative breaking, you are talking about hybrids, which use their electric part for that, but their breaking power is limited compare to pure EVs by the electric engine power and the charging limits of the smaller battery.

avhon1 6y ago

One of my personal fantasies is that the United States imposes a maximum road speed limit of 45 miles per hour (72 kilometers / hour). As a result, cars get lighter, more efficient, and safer, and trains become more popular and practical means of traveling long distances. 45 miles an hour seems like a reasonable compromise speed. At 65% the common highway speed limit of 70 mph, it's still fast enough to cross most states in a day, to travel between nearby cities in an hour or so, and to do errands in an afternoon. But a car at that speed has only 41% the kinetic energy as at 70 mph, making colisons less lethal, and has similarly less wind resistance, requiring smaller engines and less fuel. Maybe I just think trains are romantic...

clarry 6y ago
I'm conflicted on this because I'd like those gains in safety and efficiency. I think it'd also allow us to live with smaller & curvier roads, which I think are romantic and kinda relaxing. (I'm quite bored with the wide straight flats they build; those also ruin the scenery and generate lots of noise) On the other hand, cars have been getting safer and faster and more efficient, roads have been getting wider and safer.. only speed limits haven't been lifted to match. A part of me wants to live the utopia where I can get where I want to be in less than half the time it takes today. That'd make the difference between going to my parents for a coffee after work vs having to reserve a full day (if not a full weekend) for the trip. Trains are not really a solution around here.
- avhon1 6y ago
  I think speed limits have informally (and unevenly) been rising to match the capabilities of new cars and roads. I visited a new area recently, and was shocked to see that traffic was flowing at 90 mph (!) in a 70 mph zone. I was glad I wasn't driving, because not only is that a greater posted-vs-actual speed difference than I've seen before, but I've never actually driven that fast in my life. I'd have been torn between driving 80 in the right lane and being constantly passed at 10-15mph, or being white-knuckled behind some other vehicle and setting a personal landspeed record.
  - clarry 6y ago
    Maybe they have in some areas. In my case, rural Finland, it's been the same for as long as I remember. Maximum limit is 120 km/h on freeways (and there are practically none of them where I usually drive), elsewhere on bigger inter-city roads it's 100 km/h during summer and 80 km/h during winter. Lesser roads, never more than 80 km/h. And traffic never flows significantly faster than the limit. A few km/h over the limit at most. There are some weirdos who drive much faster and are constantly overtaking others, but relatively few people drive like that. If anything, it seems to me that speeding has become less common over the years as the police have tightened the limit at which they'll fine you.
    - TomMarius 6y ago
      I am from the Czech Republic. Left lane on highway is informally reserved for "going fast", as in 160-200+ km/h. Right lane is around 120-140 km/h. Oficial speed limit is 130 km/h. Regional roads are limited to 90 km/h, but people travel as fast as 160 km/h on the largest ones. Town areas are limited to 50 km/h unless said otherwise and it required automated radars to get drivers to go less than 90 km/h in many towns on major roads. People are basically behaving like it's German autobahn everywhere. Even the informal rules have adjusted - in a major city, you not only respect the right hand rule, but also give right of way to all vehicles on the more major road. The conflict is resolved by blinking headlights. Honda used to be the most popular brand here (90's and first few years of 00's).
  - 6y ago
jacobush 6y ago
You could just build better trains, it's going to take state or fed level money to do that anyway. If the trains were better, people would use them. In practice, todays 70 mph is not much different from 45 mph. You can't drive 70 mph nonstop, medium speed is lower.
- avhon1 6y ago
  Yes, my fantasy is less like "improving Amtrack" and more like "replicate Japan's Shinkansen".
  - ectospheno 6y ago
    Japan is the size of California. Replicating that across all of a larger country such as the United States isn't realistic.
- 0xffff2 6y ago
  >You can't drive 70 mph nonstop What do you mean by that? If you're covering long distances in the Western US, it's not at all uncommon to be driving 70+ for hours at a time.

_ph_ 6y ago

Having a 2 ton car to move a 60kg person from stop light to stop light is just insane That is solely determined by the energy required. And there is, where the electric car excels. A Tesla uses less than the equivalent of 2l of fuel for 100km or in other units achieves 120mpg. In situations you describe, it fares even better, as 60% of the kinetic energy built up is gained back when braking using the electric motors. So mass is much less a problem with electric cars than with combustion engines, which can't recuperate the kinetic energy.

avhon1 6y ago
Electrics are great for low-speed stop-and-go. They're not as good on a highway, though. 0% of the energy spent displacing air at 70mph is recovered.
- _ph_ 6y ago
  They are still better than any car with a combustion engine at highway speeds. They don't recuperate while driving at constant speed of course, but still they have the greater efficiency of the electric motor vs. the combustion engine. Usually they have better aerodynamics too. But the weight doesn't play a role there, only making the cars physically smaller - less air resistance - would improve the energy consumption at highway speeds.
- FrojoS 6y ago
  Yes, but weight (which is higher in electric cars) does not influence air resistance. Tesla’s btw have record low air resistance.
rootusrootus 6y ago
Regenerative braking is always, always less efficient than just not spending the energy in the first place to speed up. And there are currently more fossil fuel cars on the road with regenerative braking than there are EVs ;-)
- _ph_ 6y ago
  To use 60% less fuel, the car needs to havee appropriately less mass, so you are talking about 700kg for a 5 seated car with passengers. If you are talking about fossil fuel cars with regenerative breaking, you are talking about hybrids, which use their electric part for that, but their breaking power is limited compare to pure EVs by the electric engine power and the charging limits of the smaller battery.