The Electric Car
in [Design]
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From: JosephKK on 1 Aug 2007 00:38 MooseFET kensmith(a)rahul.net posted to sci.electronics.design: > On Jul 31, 6:48 am, John Larkin > <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> On Mon, 30 Jul 2007 23:31:20 -0700, Richard Henry >> >> >> >> <pomer...(a)hotmail.com> wrote: >> >On Jul 30, 8:25 pm, krw <k...(a)att.bizzzz> wrote: >> >> In article >> >> <1185850948.051175.139...(a)d30g2000prg.googlegroups.com>, >> >> pomer...(a)hotmail.com says... >> >> >> > On Jul 30, 7:20 pm, Jim Thompson >> >> > <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: >> >> > > On Mon, 30 Jul 2007 19:12:03 -0700, Richard Henry >> >> >> > > <pomer...(a)hotmail.com> wrote: >> >> > > >On Jul 30, 5:48 pm, Jim Thompson >> >> > > ><To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: >> >> > > >> On Mon, 30 Jul 2007 17:30:01 -0700, "J.A. Legris" >> >> >> > > >> >- I said fuel consumption will never decrease much >> >> > > >> >unless cars are much lighter, but even radically >> >> > > >> >lighter vehicles are no long-term solution on this >> >> > > >> >overpopulated planet >> >> >> > > >> Amen! I keep telling people that, and they look at me >> >> > > >> like I'm some kind of idiot. >> >> >> > > >You have also told us how you like to drive your big >> >> > > >import illegally fast and tried to rationalize it by >> >> > > >claiming that among the vehicle's luxury features is that >> >> > > >it runs more efficiently at high speed. >> >> >> > > I didn't rationalize anything. However I do agree that >> >> > > leftist weenies should be taxed more heavily to support my >> >> > > excesses ;-) >> >> >> > > And I certainly have no problem with YOU driving a tin >> >> > > can, just NOT my children and grandchildren ;-) >> >> >> > OOHH!. Think of the children... >> >> >> > You sound like a leftist weenie. >> >> >> Not at all. Not "the" children. *HIS* children. There is a >> >> difference. >> >> >> > Please explain again the more-efficient-at-higher-speed >> >> > feature. >> >> >> It's entirely possible as was explained at the time. >> >> >It was bs then and it's bs now. All fancy gearing and ignition >> >tricks will be overcome by the inevitability of the >> >non-linearity of increase of air resistance with speed. >> >> The air resistance is highly nonlinear, cubic power:speed >> roughly, whereas other losses are essentially independent of >> speed. Every car will have an optimum speed for miles/gallon, and >> it won't be zero. > > It also won't be much over about 50MPH. It takes about 15 HP to > push > a modest sized car at 50MPH. The windage losses per mile run as > just about the square of the speed. Not necessarily. My first new car got about 22 mpg at 55 mph and about 26 mpg at 70 mph. Back then i had plenty of documentation to back it up. Kinda funny, 70 mph occurred right the rmp torque peak. It couldn't be a coincidence could it?
From: JosephKK on 1 Aug 2007 00:42 MooseFET kensmith(a)rahul.net posted to sci.electronics.design: > On Jul 31, 8:19 am, Jim Thompson > <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: >> On Tue, 31 Jul 2007 08:14:21 -0700, John Larkin >> >> >> >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >On Tue, 31 Jul 2007 14:37:31 +0000, Guy Macon >> ><http://www.guymacon.com/> wrote: >> >> >>Jim Thompson wrote: >> >> >>>I don't ever recall saying "more-efficient-at-higher-speed". >> >> >>>But I guess it WOULD depend on your definition. The engine is >> >>>optimized right around 3000RPM (85MPH), but external drag is >> >>>higher. >> >> >>Assuming that "optimized" means maximum efficiency as opposed >> >>to maximum power or torque, wouldn't it be more efficient at >> >>3000 RPM in first gear? >> >> >>Part of me thinks about the far lower drag and says that it >> >>would. Part of me thinks about those pistons moving up and >> >>down more times per mile and sucking in about the same amount >> >>of fuel per cycle and says that it wouldn't. Maybe it needs >> >>an engine sized for 3000 RPM in first gear to make it work? >> >> >>Also, I can't prove it, but I suspect that hard accelerating >> >>to some speed (don't know how fast) and then shutting down >> >>the engine and coasting down, then repeating, gives the >> >>maximum fuel economy. >> >> >Interesting curve: >> >> >http://www.fueleconomy.gov/feg/driveHabits.shtml >> >> >And it is reasonable to also factor in the value of your time. >> >> >John >> >> "Remove excess weight"... don't give a leftist weenie a ride ;-) > > At those speeds it is drag not weight that matters. You shouldn't > wear a dress while driving. But my favorite gal likes wearing dresses. Oh wait, that wouldn't be drag then. I guess i will have to tell her not to wear pants.
From: Spehro Pefhany on 1 Aug 2007 01:45 On Tue, 31 Jul 2007 21:29:24 -0700, the renowned John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Tue, 31 Jul 2007 18:08:26 -0700, MooseFET <kensmith(a)rahul.net> >wrote: > >>On Jul 31, 8:19 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >>Web-Site.com> wrote: >>> On Tue, 31 Jul 2007 08:14:21 -0700, John Larkin >>> >>> >>> >>> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >On Tue, 31 Jul 2007 14:37:31 +0000, Guy Macon >>> ><http://www.guymacon.com/> wrote: >>> >>> >>Jim Thompson wrote: >>> >>> >>>I don't ever recall saying "more-efficient-at-higher-speed". >>> >>> >>>But I guess it WOULD depend on your definition. The engine is >>> >>>optimized right around 3000RPM (85MPH), but external drag is higher. >>> >>> >>Assuming that "optimized" means maximum efficiency as opposed >>> >>to maximum power or torque, wouldn't it be more efficient at >>> >>3000 RPM in first gear? >>> >>> >>Part of me thinks about the far lower drag and says that it >>> >>would. Part of me thinks about those pistons moving up and >>> >>down more times per mile and sucking in about the same amount >>> >>of fuel per cycle and says that it wouldn't. Maybe it needs >>> >>an engine sized for 3000 RPM in first gear to make it work? >>> >>> >>Also, I can't prove it, but I suspect that hard accelerating >>> >>to some speed (don't know how fast) and then shutting down >>> >>the engine and coasting down, then repeating, gives the >>> >>maximum fuel economy. >>> >>> >Interesting curve: >>> >>> >http://www.fueleconomy.gov/feg/driveHabits.shtml >>> >>> >And it is reasonable to also factor in the value of your time. >>> >>> >John >>> >>> "Remove excess weight"... don't give a leftist weenie a ride ;-) >> >>At those speeds it is drag not weight that matters. You shouldn't >>wear a dress while driving. > >You get the best mileage if you wear nothing at all. I suspect Spandex is better than nothing. More slippery than hairy surfaces and it could prevent the energy-sapping oscillation of fatty and/or dangly bits. >John Interesting that modern hybrids apparently get better gas milage in city driving rather than highway. Eg. Prius 60mpg city, 51mpg highway http://www.toyota.com/prius/specs.html Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff(a)interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
From: Richard Henry on 1 Aug 2007 01:42 On Jul 31, 10:45 pm, Spehro Pefhany <speffS...(a)interlogDOTyou.knowwhat> wrote: > On Tue, 31 Jul 2007 21:29:24 -0700, the renowned John Larkin > > > > > > <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >On Tue, 31 Jul 2007 18:08:26 -0700, MooseFET <kensm...(a)rahul.net> > >wrote: > > >>On Jul 31, 8:19 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- > >>Web-Site.com> wrote: > >>> On Tue, 31 Jul 2007 08:14:21 -0700, John Larkin > > >>> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >>> >On Tue, 31 Jul 2007 14:37:31 +0000, Guy Macon > >>> ><http://www.guymacon.com/> wrote: > > >>> >>Jim Thompson wrote: > > >>> >>>I don't ever recall saying "more-efficient-at-higher-speed". > > >>> >>>But I guess it WOULD depend on your definition. The engine is > >>> >>>optimized right around 3000RPM (85MPH), but external drag is higher. > > >>> >>Assuming that "optimized" means maximum efficiency as opposed > >>> >>to maximum power or torque, wouldn't it be more efficient at > >>> >>3000 RPM in first gear? > > >>> >>Part of me thinks about the far lower drag and says that it > >>> >>would. Part of me thinks about those pistons moving up and > >>> >>down more times per mile and sucking in about the same amount > >>> >>of fuel per cycle and says that it wouldn't. Maybe it needs > >>> >>an engine sized for 3000 RPM in first gear to make it work? > > >>> >>Also, I can't prove it, but I suspect that hard accelerating > >>> >>to some speed (don't know how fast) and then shutting down > >>> >>the engine and coasting down, then repeating, gives the > >>> >>maximum fuel economy. > > >>> >Interesting curve: > > >>> >http://www.fueleconomy.gov/feg/driveHabits.shtml > > >>> >And it is reasonable to also factor in the value of your time. > > >>> >John > > >>> "Remove excess weight"... don't give a leftist weenie a ride ;-) > > >>At those speeds it is drag not weight that matters. You shouldn't > >>wear a dress while driving. > > >You get the best mileage if you wear nothing at all. > > I suspect Spandex is better than nothing. More slippery than hairy > surfaces and it could prevent the energy-sapping oscillation of fatty > and/or dangly bits. > > >John > > Interesting that modern hybrids apparently get better gas milage in > city driving rather than highway. > > Eg. Prius 60mpg city, 51mpg highway > > http://www.toyota.com/prius/specs.html > They're going slower in the city.
From: Richard Henry on 1 Aug 2007 01:44
On Jul 31, 9:38 pm, JosephKK <joseph_barr...(a)sbcglobal.net> wrote: > MooseFET kensm...(a)rahul.net posted to sci.electronics.design: > > > > > > > On Jul 31, 6:48 am, John Larkin > > <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> On Mon, 30 Jul 2007 23:31:20 -0700, Richard Henry > > >> <pomer...(a)hotmail.com> wrote: > >> >On Jul 30, 8:25 pm, krw <k...(a)att.bizzzz> wrote: > >> >> In article > >> >> <1185850948.051175.139...(a)d30g2000prg.googlegroups.com>, > >> >> pomer...(a)hotmail.com says... > > >> >> > On Jul 30, 7:20 pm, Jim Thompson > >> >> > <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: > >> >> > > On Mon, 30 Jul 2007 19:12:03 -0700, Richard Henry > > >> >> > > <pomer...(a)hotmail.com> wrote: > >> >> > > >On Jul 30, 5:48 pm, Jim Thompson > >> >> > > ><To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: > >> >> > > >> On Mon, 30 Jul 2007 17:30:01 -0700, "J.A. Legris" > > >> >> > > >> >- I said fuel consumption will never decrease much > >> >> > > >> >unless cars are much lighter, but even radically > >> >> > > >> >lighter vehicles are no long-term solution on this > >> >> > > >> >overpopulated planet > > >> >> > > >> Amen! I keep telling people that, and they look at me > >> >> > > >> like I'm some kind of idiot. > > >> >> > > >You have also told us how you like to drive your big > >> >> > > >import illegally fast and tried to rationalize it by > >> >> > > >claiming that among the vehicle's luxury features is that > >> >> > > >it runs more efficiently at high speed. > > >> >> > > I didn't rationalize anything. However I do agree that > >> >> > > leftist weenies should be taxed more heavily to support my > >> >> > > excesses ;-) > > >> >> > > And I certainly have no problem with YOU driving a tin > >> >> > > can, just NOT my children and grandchildren ;-) > > >> >> > OOHH!. Think of the children... > > >> >> > You sound like a leftist weenie. > > >> >> Not at all. Not "the" children. *HIS* children. There is a > >> >> difference. > > >> >> > Please explain again the more-efficient-at-higher-speed > >> >> > feature. > > >> >> It's entirely possible as was explained at the time. > > >> >It was bs then and it's bs now. All fancy gearing and ignition > >> >tricks will be overcome by the inevitability of the > >> >non-linearity of increase of air resistance with speed. > > >> The air resistance is highly nonlinear, cubic power:speed > >> roughly, whereas other losses are essentially independent of > >> speed. Every car will have an optimum speed for miles/gallon, and > >> it won't be zero. > > > It also won't be much over about 50MPH. It takes about 15 HP to > > push > > a modest sized car at 50MPH. The windage losses per mile run as > > just about the square of the speed. > > Not necessarily. My first new car got about 22 mpg at 55 mph and > about 26 mpg at 70 mph. Back then i had plenty of documentation to > back it up. Kinda funny, 70 mph occurred right the rmp torque > peak. It couldn't be a coincidence could it? Documentation? The first question would be: How did you measure it? |