# Do Toyota Priuses CAUSE more pollution? **URL:** \ **Category:** Factual Questions\ **Created:** [November 2, 2011, 3:08pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629 "2011-11-02T15:08:47Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Procrustus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/procrustus/32/2994_2.png) [@Procrustus](https://boards.straightdope.com/u/Procrustus)\ **Post date:** [November 2, 2011, 6:00pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/21 "2011-11-02T18:00:00Z")
> [@Philster](#): > > Most efficient. Then please explain. When I’m using my internal combustion engine less, I seem to get better mpg. Am I wrong? ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 2, 2011, 6:01pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/22 "2011-11-02T18:01:50Z")
I drive an Insight. The dash has indicators that tell you whether or not you’re driving in what I’ll call “the sweet spot”. If you keep in the sweet spot as much as possible, you end up accelerating more slowly and taking longer to stop. One instance I can think of where doing this might cause someone else to burn more gas is if it causes them to miss a green light (and thus waste gas sitting at the red) when they otherwise would have made it. It strikes me that this wouldn’t happen often enough to offset the overall amount I save over time. Other people may also waste gas due to unjustified impatience. For example, I’ve learned that if I see a light up ahead turn red and I know that I’m going to end up waiting at it regardless, I’ll start to let up on the gas sooner than most people would. What that achieves is that I arrive at the light at a crawl and can then stop with just a little braking. This saves fuel as well as wear on the brakes and costs me nothing in time. However, I’ve noticed that sometimes when I do this the person behind me will get impatient, hit the accelerator, pull around me, and accelerate to the light, almost as if they’re making some kind of point. They gain nothing from this as I eventually drift up and stop beside them but they apparently get some kind of satisfaction from it. This behavior creates more pollution, but that is due to their impatience and stupidity and is not due to my driving a hybrid. ---
**Author:** ![GreasyJack](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@GreasyJack](https://boards.straightdope.com/u/GreasyJack)\ **Post date:** [November 2, 2011, 6:13pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/23 "2011-11-02T18:13:04Z")
It sounds like a variation on the claim that VW Beetles/other small slow (and inevitably imported) cars cause traffic jams. The argument wasn’t very compelling back then and it certainly isn’t with the Prius, which drives like a top-fuel dragster compared to those economy cars of yore. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [November 2, 2011, 7:06pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/24 "2011-11-02T19:06:46Z")
> [@Knorf](#): > > I really can’t think of any way the quote from the OP isn’t rubbish. I can, but that doesn’t make it interesting. The quote is: > [@](#): > > Prius in congested traffic will cause more emissions indirectly by slowing cars down than it will emit directly. What it appears to say (don’t know what the author actually meant, without more context, of course), is that a) congestion slows cars down (kind of by definition) b) adding more cars increases congestion, which will in some cases slow cars down more (hard to argue against, given the ‘in some cases’ limitation) c) if speeds drop low enough, this causes more gas consumption (stop-and-start traffic is clearly less fuel efficient than a nice smooth 35 mph) so therefore d) adding one more car to a road, can, if the conditions are right, decrease (by some amount) fuel efficiency for all cars caught in the congestion. e) sum the total amount of fuel wasted because of adding one car (of any type) to the existing congestion, and call it W. f) for a Prius, under certain conditions, W will be more than the amount of fuel used by the Prius itself. Which is completely logical and consistent, and may even be true under particular (but by no means all) circumstances. But isn’t on its own particularly relevant to any kind of policy, since we haven’t established how often we really have the conditions where f) is true, and whether that’s enough to outweigh the gains from a Prius in other conditions. But even if this is true under a wide enough range of situations to be significant, it’s not an argument against hybrids or electric cars; it’s an argument that a bigger difference could be made with more public transport and/or other ways to limit congestion that don’t result in more cars on the road. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [November 2, 2011, 7:19pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/25 "2011-11-02T19:19:13Z")
My Camry Hybrid will “creep” using electric power and not starting the engine. When the engine does start in this mode, it runs at efficient speed and charges the batteries even if I am standing still. In creeping stop and go traffic, the engine rarely runs, just kicks in once in a while in to charge the batteries. I can think of no circumstance where it is less efficient or more polluting than a regular car. Even on the highway, the engine, being smaller than a regular car engine for that size, is using less gas (especially,1.8L uses less than your typical V6 3.0L luxury car). Basically, the computer micromanages energy use, so that you get almost highway mileage efficiency in city driving. ---
**Author:** ![JoelUpchurch](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@JoelUpchurch](https://boards.straightdope.com/u/JoelUpchurch)\ **Post date:** [November 2, 2011, 7:31pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/26 "2011-11-02T19:31:15Z")
Maybe he means that additional resources used in making the Prius aren’t really compensated for by gasoline savings especially when you consider what a hybrid would cost without the government subsidy, where you are asking low income taxpayers to subsidize your green lifestyle. The problem is that a Prius has become a green status symbol, so a lot of people buy them when it would be better for the environment if they kept driving their old cars. There are a lot of options to consider. There are several conventional cars that get over 40mpg on the highway and there are mild hybrids and the the Natural Gas powered Civic. You could even get an electric scooter and use that for short trips. You really need to analyze your lifestyle and do the math. ---
**Author:** ![JoelUpchurch](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@JoelUpchurch](https://boards.straightdope.com/u/JoelUpchurch)\ **Post date:** [November 2, 2011, 7:50pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/27 "2011-11-02T19:50:10Z")
[http://www.wired.com/science/planetearth/magazine/16-06/ff\_heresies\_09usedcars](http://www.wired.com/science/planetearth/magazine/16-06/ff_heresies_09usedcars) This article claims that the Prius uses the energy equivalent of 1000 gallons of gasoline before it ever gets to the road. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [November 2, 2011, 7:55pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/28 "2011-11-02T19:55:38Z")
> [@Philster](#): > > The most efficient use of a Hybrid vehicle of the Prius type is to drive it in such a manner that you never need electric power and depend solely on the internal combustion engine. This simply _must_ be wrong. When the internal combustion is running, it is not only moving the car but running a charge to the battery. If the battery never gets use, then all that energy is wasted. I too am gonna need a cite on this. As far as the OP – even if it is true that Priuses accelerate more slowly and force the cars around them to accelerate more slowly, wouldn’t that _increase_ everyone’s efficiency? Has all those years of warning about being a “lead foot” been a load of bullshit? ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [November 2, 2011, 7:58pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/29 "2011-11-02T19:58:01Z")
> [@Boyo\_Jim](#): > > As far as the OP – even if it is true that Priuses accelerate more slowly and force the cars around them to accelerate more slowly, wouldn’t that _increase_ everyone’s efficiency? Has all those years of warning about being a “lead foot” been a load of bullshit? Depends on if the people behind it are slowly but surely accelerating with the Prius, or alternatively gunning the engine and braking impatiently. ---
**Author:** ![GreasyJack](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@GreasyJack](https://boards.straightdope.com/u/GreasyJack)\ **Post date:** [November 2, 2011, 8:09pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/30 "2011-11-02T20:09:27Z")
> [@Boyo\_Jim](#): > > This simply _must_ be wrong. When the internal combustion is running, it is not only moving the car but running a charge to the battery. If the battery never gets use, then all that energy is wasted. Yeah, I think he’s confused on this. With the old Honda-style hybrid system where the electric motor was a booster that only came on when you stomped on it, it was true that driving in such a way that the electric motor never came on would give you better mileage. But with the Toyota-style system the electric motor is more-or-less always on, so saying that you use the least fuel by not using the electric motor is I suppose technically true since the only way to do it is to not drive the car at all! ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 2, 2011, 8:12pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/31 "2011-11-02T20:12:28Z")
> [@JoelUpchurch](#): > > Maybe he means that additional resources used in making the Prius aren’t really compensated for by gasoline savings especially when you consider what a hybrid would cost without the government subsidy, where you are asking low income taxpayers to subsidize your green lifestyle. > > The problem is that a Prius has become a green status symbol, so a lot of people buy them when it would be better for the environment if they kept driving their old cars. > > There are a lot of options to consider. There are several conventional cars that get over 40mpg on the highway and there are mild hybrids and the the Natural Gas powered Civic. You could even get an electric scooter and use that for short trips. You really need to analyze your lifestyle and do the math. I purchased my insight because my old Saturn was dead and it would have cost more than it was worth to repair it. So in my case at least, I was going to buy another car anyway. Does the government subsidize hybrids? If you’re talking about the tax deduction, mine wasn’t eligible but I understand that some are. In any case, I’m not sure how a government subsidy would make a hybrid more or less polluting, which is what we’re discussing here. I’m also not sure how it specifically impacts low income tax payers. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [November 2, 2011, 8:51pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/32 "2011-11-02T20:51:15Z")
> [@JoelUpchurch](#): > > [http://www.wired.com/science/planetearth/magazine/16-06/ff\_heresies\_09usedcars](http://www.wired.com/science/planetearth/magazine/16-06/ff_heresies_09usedcars) > > This article claims that the Prius uses the energy equivalent of 1000 gallons of gasoline before it ever gets to the road. Right, but their recommendations are for a 10-year old Tercel or an ancient Geo. I’ll stick with something that runs. ---
**Author:** ![Strassia](https://avatars.discourse-cdn.com/v4/letter/s/e8c25b/32.png) [@Strassia](https://boards.straightdope.com/u/Strassia)\ **Post date:** [November 2, 2011, 8:53pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/33 "2011-11-02T20:53:00Z")
> [@Philster](#): > > The most efficient use of a Hybrid vehicle of the Prius type is to drive it in such a manner that you never need electric power and depend solely on the internal combustion engine. The only way that would work is if you slowly accelerate and maintain constant speed on a perfectly level road. That would mean no regenerative breaking and any energy diverted to charge the battery would be wasted. In the real world, if you drive correctly, the battery stores energy that would normally be lost to braking (stopping at lights or in traffic and going down hill) and uses that energy when needed (accelerating, uphill). I got my best MPG in my Prius (averaged at around 53mpg) when I commuted from [San Mateo to Livermore, CA](http://g.co/maps/eaf8d). That involved going over a not insignificant mountain. If I kept my speed below 50 on the way up, I would crest with less than 25% of my battery charge, and then coast all the way down and end up with a full charge. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 2, 2011, 8:56pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/34 "2011-11-02T20:56:38Z")
> [@JoelUpchurch](#): > > [http://www.wired.com/science/planetearth/magazine/16-06/ff\_heresies\_09usedcars](http://www.wired.com/science/planetearth/magazine/16-06/ff_heresies_09usedcars) > > This article claims that the Prius uses the energy equivalent of 1000 gallons of gasoline before it ever gets to the road. From your cite: > [@](#): > > In 2006, an Oregon market research firm released an incendiary 500-page report. Its claim: A Humvee (13 miles per gallon city, 16 highway) uses less energy than a Prius (48 city, 45 highway). Scientists quickly debunked the study, but the Hummer lovers got one thing right. Pound for pound, making a Prius contributes more carbon to the atmosphere than making a Hummer, largely due to the environmental cost of the 30 pounds of nickel in the hybrid’s battery. **Of course, the hybrid quickly erases that carbon deficit on the road, thanks to its vastly superior fuel economy.** Note the part I bolded. ---
**Author:** ![JoelUpchurch](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@JoelUpchurch](https://boards.straightdope.com/u/JoelUpchurch)\ **Post date:** [November 2, 2011, 9:14pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/35 "2011-11-02T21:14:18Z")
> [@davidm](#): > > I purchased my insight because my old Saturn was dead and it would have cost more than it was worth to repair it. So in my case at least, I was going to buy another car anyway. > > Does the government subsidize hybrids? If you’re talking about the tax deduction, mine wasn’t eligible but I understand that some are. > > In any case, I’m not sure how a government subsidy would make a hybrid more or less polluting, which is what we’re discussing here. > > I’m also not sure how it specifically impacts low income tax payers. Hybrids get a **Tax Credit** , not a deduction, there may be additional state tax breaks. [http://openhousesinboston.com/articles/finance-2/taxes-2/irs-announces-tax-credits-for-toyota-prius/](http://openhousesinboston.com/articles/finance-2/taxes-2/irs-announces-tax-credits-for-toyota-prius/) On the current models the PHEV models get the biggest credits. [http://www.thedetroitbureau.com/2011/09/toyota-prices-prius-plug-in-at-unexpected-32760/](http://www.thedetroitbureau.com/2011/09/toyota-prices-prius-plug-in-at-unexpected-32760/) I notice that Brad Templeton also uses the Insight as his hybrid base comparison, for hybrids. [http://ideas.4brad.com/green-u-s-transit-whopping-myth](http://ideas.4brad.com/green-u-s-transit-whopping-myth) I was excited when I heard that Honda was going to release a hybrid Fit with a Insight drive train. Too bad they only released in in Japan. The Fit is now the best selling car in Japan. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 2, 2011, 9:19pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/36 "2011-11-02T21:19:42Z")
Yes, I meant tax credit, not sure why I said deduction. In any case my Insight didn’t qualify. ---
**Author:** ![JoelUpchurch](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@JoelUpchurch](https://boards.straightdope.com/u/JoelUpchurch)\ **Post date:** [November 2, 2011, 9:21pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/37 "2011-11-02T21:21:04Z")
> [@davidm](#): > > From your cite:Note the part I bolded. That is comparing a Hummer to a Prius. If you compare a Prius to a Fiesta, then you will never break even, unless you do most of your of your driving in the city. ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [November 2, 2011, 9:26pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/38 "2011-11-02T21:26:00Z")
You have to buy the right vehicle based on how you’ll use it. The Insight is the opposite of the Prius in that it gets better mileage on the highway than in the city. ---
**Author:** ![tanstaafl](https://avatars.discourse-cdn.com/v4/letter/t/ba8739/32.png) [@tanstaafl](https://boards.straightdope.com/u/tanstaafl)\ **Post date:** [November 2, 2011, 9:30pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/39 "2011-11-02T21:30:55Z")
I suspect they are talking about [hypermiling](http://en.wikipedia.org/wiki/Hypermiling). Some Prius owners drive in such a way to maximize their fuel economy, even though this may conflict with the rest of the traffic flow. I have seen interviews (which I can’t find now) where Hypermilers talk about doing things like maintaining steady, sub-speed limit speeds on the Interstate (say, driving at 50) because it gives them their maximum MPG. Their response to the angry drivers being held up behind them was “Well, too bad for them; I’m driving at a legal speed and saving gas. What are they in such a hurry for anyway”. So they may be talking about the behavior of a subset of Prius (or other hybrid) owners and attributing it to the vehicle itself. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [November 2, 2011, 9:36pm UTC](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629/40 "2011-11-02T21:36:18Z")
> [@JoelUpchurch](#): > > That is comparing a Hummer to a Prius. If you compare a Prius to a Fiesta, then you will never break even, unless you do most of your of your driving in the city. According to EPA’s **combined** (highway+city) fuel economy rating, the Prius is 50% more efficient than the Fiesta (50 mpg vs. 33 mpg). The savings in gas adds up to 1000 gallons after 100,000 miles of driving. [Previous page](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629.md?page=1) [Next page](https://boards.straightdope.com/t/do-toyota-priuses-cause-more-pollution/601629.md?page=3)