The Electric Car
in [Design]
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From: Don Klipstein on 5 Aug 2007 11:41 In article <f93f3v$tbm$4(a)jasen.is-a-geek.org>, Jasen Betts wrote: >On 2007-08-03, Eeyore <rabbitsfriendsandrelations(a)hotmail.com> wrote: >> >> Exactly why do you think car's *aren't* fitted with skinny tyres ? > >so they can give a good ride with mediocre suspension. I would suspect greater tread area and lower ratio of vehicle weight to tread area would increase the life of the tread. If there was not a significant disadvantage of skinny tires (with higher pressure), then I would think cars would be using them to get the tire weight down. If a car can lose say 50 pounds or more of weight that counts almost double during acceleration, it appears to me that city gas mileage could increase by a significant fraction of an MPG and automakers would love to do that with at least some of their cars for CAFE purposes. - Don Klipstein (don(a)misty.com)
From: MooseFET on 5 Aug 2007 15:41 On Aug 5, 8:41 am, d...(a)manx.misty.com (Don Klipstein) wrote: > In article <f93f3v$tb...(a)jasen.is-a-geek.org>, Jasen Betts wrote: > >On 2007-08-03, Eeyore <rabbitsfriendsandrelati...(a)hotmail.com> wrote: > > >> Exactly why do you think car's *aren't* fitted with skinny tyres ? > > >so they can give a good ride with mediocre suspension. > > I would suspect greater tread area and lower ratio of vehicle weight to > tread area would increase the life of the tread. It does up to a point. > If there was not a significant disadvantage of skinny tires (with > higher pressure), then I would think cars would be using them to get the > tire weight down. If you can't sell the car, that is a disadvantage. Car makers put all sorts of fancy stuff on the outside of cars that increase drag but improve sales. There is also a ride quality issue. A thinner tire at higher pressure makes a low loss spring that without a well designed suspension, would make the ride bouncier. > If a car can lose say 50 pounds or more of weight that > counts almost double during acceleration, it appears to me that city gas > mileage could increase by a significant fraction of an MPG and automakers > would love to do that with at least some of their cars for CAFE purposes. > > - Don Klipstein (d...(a)misty.com)
From: JosephKK on 6 Aug 2007 23:21 Richard Henry pomerado(a)hotmail.com posted to sci.electronics.design: > On Aug 1, 11:01 pm, JosephKK <joseph_barr...(a)sbcglobal.net> wrote: >> Richard Henry pomer...(a)hotmail.com posted to >> sci.electronics.design: >> >> >> >> >> >> > On Jul 31, 9:38 pm, JosephKK <joseph_barr...(a)sbcglobal.net> >> > wrote: >> >> MooseFET kensm...(a)rahul.net posted to sci.electronics.design: >> <snip> >> >> 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? >> >> Quite simply, miles traveled divided by fuel to top up again. >> With trip the odometer it was very easy. > > So you drove 70 mph between fillups? Yep. Cross country runs, 250 to 1000 miles at a crack.
From: JosephKK on 6 Aug 2007 23:44 Eeyore rabbitsfriendsandrelations(a)hotmail.com posted to sci.electronics.design: > > > Nobody wrote: > >> None of the major car makers are going to abandon ICE technology >> soon, so they will be looking to "dual-purpose" as much of their >> existing technology and infrastructure as possible. > > V8 hybrids ? Don't be so ridiculous. > > If US auto makers don't change their ways soon, they'll be out of > business. > > Graham Please look at the proposed 2009 Cadillac Escalade.
From: JosephKK on 6 Aug 2007 23:48
Mark makolber(a)yahoo.com posted to sci.electronics.design: > >> >> It seems to just argued against using any electric motors at all. >> > > Yep, I think the small batteries and electric motor in the Prius > are there for only 2 reasons.. > > 1) efficency gained by regenerative braking > 2) improve the acceleration so the ICE can be smaller also > improving the efficency. > > If you had the small ICE without the acceleration boost provided > by > the electrics, the acceleration would be poor and people would > not like the "drivablility". > > Intersting to note that a flywheel could provide the same > advantage. > > In fact I tend to think of the battery and electric motor in the > Prius is just an electric implementation of a flywheel. > > Mark > > > > > > Mark Yes, and flywheels bring their own issues with changes yaw, pitch and roll. There will have to be space for the flywheel to spin not only during normal driving but the vehicle must not become a hazard if it rolls over in any direction or spins out. |