# Are Americans really more energy efficient then the rest of the world? **URL:** \ **Category:** Factual Questions\ **Created:** [February 13, 2005, 7:25am UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851 "2005-02-13T07:25:30Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![Blown\_Injected](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@Blown\_Injected](https://boards.straightdope.com/u/Blown_Injected)\ **Post date:** [February 14, 2005, 2:08pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/21 "2005-02-14T14:08:52Z")
> [@Rayne Man](#): > > The other voltage available in the UK is what is knows as 3 phase … > and do not have to resort a second source,as in the US. The 3 phase supply can run even larger current devices , hence the use in industry. As in the US??? Triple Phase is common in industry it is generated that way just not transmitted to residential homes - it is just like a third hot wire in the box. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [February 14, 2005, 3:00pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/22 "2005-02-14T15:00:05Z")
> [@SavageNarce](#): > > Wattage (the power consumption of an appliance) is volts multiplied by amperes. A 1200-watt toaster on a 120-volt circuit will draw 10 amps. The same toaster on a 240-volt circuit will draw 5 amps. But they both consume the same amount of power. A toaster which draws 10 amps when 120 volts is applied has an internal resistance of 12 ohms (since V = I R.) If you then take that same toaster, with the same internal resistance, and apply 240 volts to it, then it will draw 20 amps, not 5 amps, and therefore will consume 4800 watts. In general, the power dissipated in a device is given by P = V[sup]2[/sup]/R; so if you keep your resistance constant and crank up the voltage, your power consumption will go up too. Similarly, if you want to dissipate a given amount of power in your device, then you have to increase the resistance of your toaster as the voltage increases. My point was that a 100-W light bulb from the States is designed to dissipate 100 W when plugged into a 120-V circuit, and a 100-W light bulb from Europe is designed to dissipate 100 W when plugged into a 240-V circuit; but if you took an American bulb and applied 240 V to it, it wouldn’t consume 100 W since the engineers who designed it assumed that it would be plugged in to a 120-V circuit. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [February 14, 2005, 3:11pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/23 "2005-02-14T15:11:23Z")
> [@Rayne Man](#): > > The other voltage available in the UK is what is knows as 3 phase and is rated at 415 volts. This is never used in domestic situations. only in industrial and commercial premises. This is because we can run heavy current devices such as heaters on the ordinary 230 volt supply and do not have to resort a second source,as in the US. The 3 phase supply can run even larger current devices , hence the use in industry. I’m not a EE, but it’s my understanding that all large-scale electrical generators worldwide are 3-phase. In industrial use, 3-phase motors are also commonly used, because you can get a much more powerful motor for a given physical size using 3-phase windings. Aboard U.S. Navy ships/subs, the electrical turbogenerators and motors are 3-phase 450V. In civilian life, I believe that 3-phase 480V motors are often used in the U.S. ---
**Author:** ![Fuji\_Kitakyusho](https://avatars.discourse-cdn.com/v4/letter/f/f0a364/32.png) [@Fuji\_Kitakyusho](https://boards.straightdope.com/u/Fuji_Kitakyusho)\ **Post date:** [February 14, 2005, 3:21pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/24 "2005-02-14T15:21:22Z")
3 phase is standard for primary distribution, but on secondary distribution is typically only routed to commercial or industrial districts as far as I know. I think the average residential homeowner would have a tough time arranging 3 phase supply. YMMV. My truck is a 7.3 L V8 diesel, from 1994. That same vehicle in the current model year offers an engine which is only 6.0 L, but which exceeds the torque and power specifications of mine. So improvements are definitely being made. I agree that energy consumption per capita is a poor measure of energy efficiency, for the reasons that \*\* Same Stone \*\* suggested. Most vehicles here have block heaters which are plugged in overnight in the winter. Probably the most significant factor is that of population density, as there are energy requirements in maintaining infrastructure that do not correlate well with population numbers. As an example, look at kilometers of highway per capita. ---
**Author:** ![Nunavut\_Boy](https://avatars.discourse-cdn.com/v4/letter/n/e95f7d/32.png) [@Nunavut\_Boy](https://boards.straightdope.com/u/Nunavut_Boy)\ **Post date:** [February 14, 2005, 3:31pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/25 "2005-02-14T15:31:27Z")
> [@Blown & Injected](#): > > Thanks **Sam** - Yeah, the transmission lines are often in the 100K volt range. > > BTW, GM has a new engine for the Vette. It is a 7.0 liter, cam in block, 2 valve push-rod engine that will spin over 7,000 rpm’s. I am certain that it is an extremely efficient engine. Just because it is big and powerful does not mean that is does not efficiently use the gas it gets. There is nothing right now that I can think of that would make that engine even more efficient than a couple of turbos - especially if ya need to go over 200 🙂 One could argue that a 7.0L engine is completely unnecessary. Take all that technology and refinements you just mentioned and stick 'em in, say, a 3.5L engine. There. You’ve just halved your fuel consumption. And who the hell needs to get up past 200MPH (unless you are a racecar driver)? Notice I said “one” and not “I” ---
**Author:** ![CapnPitt](https://avatars.discourse-cdn.com/v4/letter/c/edb3f5/32.png) [@CapnPitt](https://boards.straightdope.com/u/CapnPitt)\ **Post date:** [February 14, 2005, 6:54pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/26 "2005-02-14T18:54:54Z")
> [@MikeS](#): > > I’m no economist either, but if you’re interested in that data (which the DOE calls “Energy Intensity”), [here it is.](http://www.eia.doe.gov/pub/international/iealf/tablee1g.xls) (Again, Excel format.) Thanks Mike. I think everyone else has answered the OP, but I still think this might be a “fairer” measure of efficient use than just total consumption. But again, that’s probably another thread. ---
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [February 14, 2005, 7:35pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/27 "2005-02-14T19:35:08Z")
> [@Nunavut Boy](#): > > One could argue that a 7.0L engine is completely unnecessary. Take all that technology and refinements you just mentioned and stick 'em in, say, a 3.5L engine. There. You’ve just halved your fuel consumption. And who the hell needs to get up past 200MPH (unless you are a racecar driver)? How do you derive a 50% reduction in fuel consumption from a 50% reduction in displacement? I think it’s a bit more complicated than that. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 14, 2005, 8:24pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/28 "2005-02-14T20:24:01Z")
> [@](#): > > Surely building an airconditioned city of light in the middle of a desert isn’t going to help the national average if you’re not using solar energy. It should be noted that Las Vegas is right next to Hoover Dam, one of the largest hydroelectric installations in the world. That cheap hydro power is one of the reasons why there’s so much energy consumption in Vegas: Because they can. ---
**Author:** ![Pushkin](https://avatars.discourse-cdn.com/v4/letter/p/ee59a6/32.png) [@Pushkin](https://boards.straightdope.com/u/Pushkin)\ **Post date:** [February 15, 2005, 9:48am UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/29 "2005-02-15T09:48:35Z")
> [@Malacandra](#): > > We consider a 2.3 litre V **6** pretty hot for family transport Yup, my Dad’s old Volvo 740 was his largest car by engine capacity (although it had a 4 cylinder engine) > [@Malacandra](#): > > there used to be a fair number of 3-litre and 3.5 litre engines about the place, but even they were considered big. Yup, my Dad’s dream car used to be a MGB GT V8, with a 3.5 litre Rover engine. He could have had one cheap too, a customer of his in the bank had one in his garage. His son was an airline pilot and could afford the running costs but was rarely home to use it. Unfortunately Dad couldn’t get insurance for it. He also could also have had his hands on an E-Type Jag but again he had to stick to a Lancia Beta Coupe instead for practicality’s sake (my birth being just round the corner 😃 ) But enough of the nostalgic thread hijacking! ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [February 15, 2005, 5:59pm UTC](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851/30 "2005-02-15T17:59:36Z")
> [@mks57](#): > > How do you derive a 50% reduction in fuel consumption from a 50% reduction in displacement? I think it’s a bit more complicated than that. You are correct, you **don’t** halve it. Just because an engine has twice the displacement does not mean it uses twice the fuel. The engine uses the fuel needed to generate the power required to operate the motor vehicle. Larger engines can be less efficient at non-peak loads, and have other factors such as greater bearing losses and so forth, or be of an older design (as they often are in practice), but trying to say that going from a 7l to a 3.5l engine will halve your fuel consumption under the same loading conditions is completely and totally **incorrect**. > [@Fuji Kitakyusho](#): > > My truck is a 7.3 L V8 diesel, from 1994. That same vehicle in the current model year offers an engine which is only 6.0 L, but which exceeds the torque and power specifications of mine. This is comparing red apples to green apples. Just because on paper the engine may have a greater horsepower and/or torque does not mean that it has more effective, operating power and/or torque under the normal operating rpm range of the vehicle. This is true in the case when people compare their 250+hp turbo 4 to my 225hp Mustang. My Mustang has an very fat torque curve in the normal driving range that means I can pull away at 20mph in 5th gear without lugging, whereas my friend with the turbo 4 doesn’t develop his peak power until 7000 rpm or so. If he puts his car in 5th at under 40 it lugs and stalls. A truck may benefit more from an engine with lower **peak** power and **peak** torque, depending on the shape of the torque and power curves, and the rpm range they develop the bulk of the area under that curve. It’s therefore impossible to make a blanket statement on this without seeing said curves. [Previous page](https://boards.straightdope.com/t/are-americans-really-more-energy-efficient-then-the-rest-of-the-world/289851.md?page=1)