5 ms·

100 mpg Prius

7 points by kirubakaran 19y ago

dkokelley 19y ago
I see that it's still more expensive to go green than to bite the gas-price bullet. Still, 100mpg is a good marketing angle for them. Let's look at it this way: Assume average person drives 1000 miles/month Assume gas costs $4/gallon Assume Prius gets 100mpg, and other cars get 20mpg A Prius driver with the conversion kit spends $40/month on gas. A typical car driver spends $200/month on gas. A prius driver saves $160 per month for driving the prius. It will take 5.2 years to re-earn the $10,000 upgrade. This does not include the price for a prius, which I was surprised to find has come down quite a bit. A 2008 prius base model costs $21,100.
- Alex3917 19y ago
  What if you factor in the cost of carbon?
  - dkokelley 19y ago
    Please explain. Are you referring to the environmental, intangible "cost" of carbon emissions, or maybe the cost of cleaning them from the environment? What is the cost of carbon? (To be clear, I was trying to evaluate the 2 cars economically, without the consideration of carbon footprint or other moral duty to the environment to get in the way of the calculations.)
    - Alex3917 19y ago
      I meant the expected cost of carbon once a cap-and-trade system is implemented. All three candidates favor putting such a system in place, so there is something like a 90% chance of getting this legislation enacted sometime within the next 24 months. McCain's bill actually is expected to go up for a vote the week of June 2nd. The calculation should ideally take into account the fact that most people would charge their cars at night when electricity is cheaper and a greater percentage of the mix comes from renewable sources (because of wind power).
      - dkokelley 19y ago
        Ok I get it now. I actually have no idea what a the cost of such a system will be, because I hadn't heard much about the legislation you mentioned. I assume that once something like that passes, it will help move more people to electric vehicles. Personally, I'm saving for the Tesla Roadster (http://www.teslamotors.com/ http://www.teslamotors.com/).
- ssharp 19y ago
  This is true to a point. The cost of hybrids needs to come down (or reintroduce tax rebates for Toyota with plug-ins in two years) for hybrids to hit a faster break-even point than 5 years unless gas skyrockets to $5-6 / gallon. A good portion of current of the hybrid market doesn't really care about breaking even or saving that much on gas - they're more concerned with the social factors - reducing pollution and dependence on foreign oil. In order to really push the rest of American towards alternative-fuel or electric vehicles, the cost is going to have to come down.
jws 19y ago
Stop this silliness now. Claiming a "miles per gallon" figure when you get significant amount of your energy from another source is just silly. Its like claiming 100mpg if you start at the top of Pike's Peak. I propose we popularize "kilometers per megajoule", or kpm. A gallon of gas has 130 megajoules, 33% efficient internal combustion engine, so a 60mpg car would be something like 2.5kpm. This will nicely separate separate efficiency of motion from energy source. People should be able to easily reason about a 2.5kpm vehicle with a 20 megajoule plugin chargeable battery. (I think, no one has check these numbers. Notice I had to come back and edit for the engine efficiency once already, so they should be scrutinized.) The ugly part is how to think about the internal combustion engine. You may have 1300 mega joules in the gas tank, but you will lose 60-70% of those in your engine before they meet the drivetrain. I leave that part as an exercise to the reader.
- deleted 19y ago
  [deleted]
- brookr 19y ago
  But from an environmental perspective, perhaps people are more concerned about the trade-off between carbon emissions and distance traveled. Efficiency measures would be great way to evaluate drive sources, and would perhaps be very revealing when internal combustion is exposed as being so inefficient. But perhaps a rating of carbon "moles per kilometer" would be a better indication of environmental impact of any motion source. It would be interesting to compare even with walking, running, and biking (at different speeds), as you exhale (significantly smaller) amounts of carbon dioxide (and none of the worst carbon offender, CO, thankfully). Here too, the energy source that you are plugging this module into could greatly vary your MPK.
brookr 19y ago
Problem is, most people's primary electricity source is coal-burning power plants that do not provide significantly lower carbon emissions (depends on the efficiency of the module, of course). However, more municipalities (like here around seattle) are offering wind-sourced power to homes who "green-up". There is a $12/month additional charge, but it is a great way to reduce overall emissions.
- ssharp 19y ago
  That's not a problem at all. If you compare the raw power usage, it's still both cleaner and more efficient to use electricity than gas. Also, gas engines aren't going to get that much cleaner, whereas the energy grid is only going to get cleaner with cleaner coal, nuclear, and renewables. I wouldn't be surprised if in 15 years from now, if half of all new cars sold use electricity as their primary source. Energy independence should be a goal for every country, but especially for a country like the U.S. that uses so much oil.

7 points by kirubakaran 19y ago

I see that it's still more expensive to go green than to bite the gas-price bullet. Still, 100mpg is a good marketing angle for them. Let's look at it this way: Assume average person drives 1000 miles/month Assume gas costs $4/gallon Assume Prius gets 100mpg, and other cars get 20mpg A Prius driver with the conversion kit spends $40/month on gas. A typical car driver spends $200/month on gas. A prius driver saves $160 per month for driving the prius. It will take 5.2 years to re-earn the $10,000 upgrade. This does not include the price for a prius, which I was surprised to find has come down quite a bit. A 2008 prius base model costs $21,100.

Alex3917 19y ago
What if you factor in the cost of carbon?
- dkokelley 19y ago
  Please explain. Are you referring to the environmental, intangible "cost" of carbon emissions, or maybe the cost of cleaning them from the environment? What is the cost of carbon? (To be clear, I was trying to evaluate the 2 cars economically, without the consideration of carbon footprint or other moral duty to the environment to get in the way of the calculations.)
  - Alex3917 19y ago
    I meant the expected cost of carbon once a cap-and-trade system is implemented. All three candidates favor putting such a system in place, so there is something like a 90% chance of getting this legislation enacted sometime within the next 24 months. McCain's bill actually is expected to go up for a vote the week of June 2nd. The calculation should ideally take into account the fact that most people would charge their cars at night when electricity is cheaper and a greater percentage of the mix comes from renewable sources (because of wind power).
    - dkokelley 19y ago
      Ok I get it now. I actually have no idea what a the cost of such a system will be, because I hadn't heard much about the legislation you mentioned. I assume that once something like that passes, it will help move more people to electric vehicles. Personally, I'm saving for the Tesla Roadster (http://www.teslamotors.com/ http://www.teslamotors.com/).
ssharp 19y ago
This is true to a point. The cost of hybrids needs to come down (or reintroduce tax rebates for Toyota with plug-ins in two years) for hybrids to hit a faster break-even point than 5 years unless gas skyrockets to $5-6 / gallon. A good portion of current of the hybrid market doesn't really care about breaking even or saving that much on gas - they're more concerned with the social factors - reducing pollution and dependence on foreign oil. In order to really push the rest of American towards alternative-fuel or electric vehicles, the cost is going to have to come down.

jws 19y ago

Stop this silliness now. Claiming a "miles per gallon" figure when you get significant amount of your energy from another source is just silly. Its like claiming 100mpg if you start at the top of Pike's Peak. I propose we popularize "kilometers per megajoule", or kpm. A gallon of gas has 130 megajoules, 33% efficient internal combustion engine, so a 60mpg car would be something like 2.5kpm. This will nicely separate separate efficiency of motion from energy source. People should be able to easily reason about a 2.5kpm vehicle with a 20 megajoule plugin chargeable battery. (I think, no one has check these numbers. Notice I had to come back and edit for the engine efficiency once already, so they should be scrutinized.) The ugly part is how to think about the internal combustion engine. You may have 1300 mega joules in the gas tank, but you will lose 60-70% of those in your engine before they meet the drivetrain. I leave that part as an exercise to the reader.

deleted 19y ago
[deleted]
brookr 19y ago
But from an environmental perspective, perhaps people are more concerned about the trade-off between carbon emissions and distance traveled. Efficiency measures would be great way to evaluate drive sources, and would perhaps be very revealing when internal combustion is exposed as being so inefficient. But perhaps a rating of carbon "moles per kilometer" would be a better indication of environmental impact of any motion source. It would be interesting to compare even with walking, running, and biking (at different speeds), as you exhale (significantly smaller) amounts of carbon dioxide (and none of the worst carbon offender, CO, thankfully). Here too, the energy source that you are plugging this module into could greatly vary your MPK.

brookr 19y ago

Problem is, most people's primary electricity source is coal-burning power plants that do not provide significantly lower carbon emissions (depends on the efficiency of the module, of course). However, more municipalities (like here around seattle) are offering wind-sourced power to homes who "green-up". There is a $12/month additional charge, but it is a great way to reduce overall emissions.

ssharp 19y ago
That's not a problem at all. If you compare the raw power usage, it's still both cleaner and more efficient to use electricity than gas. Also, gas engines aren't going to get that much cleaner, whereas the energy grid is only going to get cleaner with cleaner coal, nuclear, and renewables. I wouldn't be surprised if in 15 years from now, if half of all new cars sold use electricity as their primary source. Energy independence should be a goal for every country, but especially for a country like the U.S. that uses so much oil.