On another discussion list, I asked users in the Colorado Rockies (and elsewhere) if using the foot-pound to kwh conversion rate provided a reasonable estimate of kwh consumption and regeneration numbers. It seemed to. So for a Model Y at 4416 pounds with two adults and luggage, the vehicle weight would be close to 5,000 pounds. The conversion formula is:
1 ft-lb = 3.7661609675872E-7 kWh 5,000 * 1,000 * 3.766E-7 = 1.42 kwh or 1 kwh for every 700 foot increase in elevation. A rise of 7,000 feet would be an additional usage of around 10 kwh divided by car efficiency. so a 5,000 pound Model Y ascending a 1,000 foot rise would use an additional 1.42 kwh divided by car efficiency. Regen would be the same value times regen efficiency. A car that was 90% efficient would use 1.57 kwh in the climb. A car that has 80% regen efficiency would regain 1.14 kwh. A car going up and back down that 1,000 foot rise would lose 0.43 kwh. Does that make sense? On Mon, Jan 3, 2022 at 3:09 PM (-Phil-) via EV <ev@lists.evdl.org> wrote: > > The cool thing about an efficient EV powertrain is regen can give you a lot > of this back when you go back down the hill! > > On Mon, Jan 3, 2022 at 8:29 AM Peter VanDerWal via EV <ev@lists.evdl.org> > wrote: > > > Well, until you start going uphill then weight becomes significant again. > > > > FWIW, back in the day I noticed that my diesel F-250 was significantly > > better at coasting than my other vehicles. Yeah it had crap aerodynamics, > > but 3 tons of inertia does make a difference > > > > My PGP public key: https://vanderwal.us/evdl_pgp.key > > > > December 30, 2021 6:02 PM, "Bill Dube via EV" <ev@lists.evdl.org> wrote: > > > > > On 12/31/2021 4:17 AM, paul dove via EV wrote: > > > > > >> Well, that’s not how efficiency is measured but I think I know what you > > mean. The Wh per mile is > > >> mostly a function of weight. Aero starts to weigh in around 55mph. On > > conversions a good estimate > > >> is weight divided by 10. My car weighs 3100 lbs with me in it and I got > > around 300wh/m. Tesla beat > > >> this by making the battery a larger percentage of total weight by using > > aluminum. No one else comes > > >> close. I think the Bolt is close to the rule of thumb. > > > > > > At the wall is probably the best way to measure efficiency. It is > > > what the consumer cares about most. That is what I would care about, for > > > sure. > > > > > > Weight doesn't make nearly the difference in efficiency as does the > > > frontal area. > > > > > > Often, the weight of a car is sometimes reflected in the frontal > > > area, however, but there is not much correlation. > > > > > > Rolling resistance is roughly proportional to speed (and the > > > weight,) while aerodynamic drag is proportional to the frontal area and > > > the _cube_ of speed. That cube term adds up very quickly. Aero drag > > > starts to dominate at about 30 mph. Nothing else matters much over ~60 > > mph. > > > > > > Bill D. > > > > > > _______________________________________________ > > > Address messages to ev@lists.evdl.org > > > No other addresses in TO and CC fields > > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > > ARCHIVE: http://www.evdl.org/archive > > > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > _______________________________________________ > > Address messages to ev@lists.evdl.org > > No other addresses in TO and CC fields > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > ARCHIVE: http://www.evdl.org/archive/ > > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20220103/8d4c1dd3/attachment.html> > _______________________________________________ > Address messages to ev@lists.evdl.org > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org _______________________________________________ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
