It’s mostly due to the ratio of battery weight to vehicle weight. A much larger percentage of the weight is batteries compared to other vehicles and conversions
Sent from AT&T Yahoo Mail for iPhone On Thursday, October 26, 2023, 2:57 PM, Lee Hart via EV <ev@lists.evdl.org> wrote: Tesla probably has a lot more tricks up its sleeve than just aerodynamics and motor/controller efficiency. The old DC series motors and controllers were each about 90% efficient; so about 80% overall. Tesla's combined motor and controller have improved that to perhaps 90%; but that's only a 10 gain. As has been said, the Cd is better. but the frontal area is also more than a typical small car conversion. So again, not that much of a gain. It could be that Tesla is using special tires. I found a considerable improvement in mpg between "normal" tires and the special Bridgestone Potenzas that came on my Prius, and the Goodyear Invictas that came on my Plymouth minivan. I got a similar improvement in range when I used these particular tires on my EVs. Brake drag is another factor. Most cars let the pads just barely touch the rotors. EVs take special pains to design the brakes to fully retract the pads. Still another is wheel alignment. Most cars are designed with deliberate toe-in in front, and sometimes in the rear wheels as well. I think this is done to improve handling. But it increases rolling resistance. One of Solectria's tricks was to meticulously adjust their EVs for zero toe-in. You could easily push a Solectria Force with one hand. Lee -- Excellence does not require perfection. -- Henry James -- Lee A. Hart http://www.sunrise-ev.com -----Original Message----- From: Electric Vehicle Discussion List <ev@lists.evdl.org> Sent: Oct 26, 2023 11:37 AM To: Electric Vehicle Discussion List <ev@lists.evdl.org> Cc: (-Phil-) <p...@ingineerix.com> Subject: Re: [EVDL] Tesla-Y KWH Efficiency Tesla's PMSRM motor and SiCFET inverter tech is also pretty amazing for efficiency. FYI: I have a 2018 Model 3 and I tow all the time with no issues. Several companies make a bolt-on hitch. On Thu, Oct 26, 2023 at 7:48 AM Peri Hartman via EV wrote: > I think you nailed it. The Y has a Cd of 0.23 according to a few sites I > checked. That's a pretty awesome number compared to almost any other > car. > > If your test driving includes a lot of steep hills or starts and stops, > the Cd probably won't make much difference. I presume you are driving > mostly at constant speeds on relatively level ground. In the latter > case, the rolling resistance and Cd are the important factors. > > Also, residential streets versus highways make a difference, of course. > The Cd has little effect until you get close to highway speeds. > > Peri > > > > > > ------ Original Message ------ > From: "Mark E. Hanson via EV" > To: "'Electric Vehicle Discussion List'" > Cc: markehans...@gmail.com > Sent: 26-Oct-23 06:58:13 > Subject: [EVDL] Tesla-Y KWH Efficiency > > >Hi Folks, > > > > > > > >I was curious why my Tesla-Y that's 4400 pounds came out ahead of my > >conversions over the years (80's-2011) that averaged 334 watt hours per > mile > >or 3 miles per KWH (weighed closer to 2000lbs). The Tesla-Y display which > >is DC at the battery, shows 244 watt hours per mile. I measured at the AC > >outlet (actual KWH usage) with the KWH meter on OpenEVSE.com, also matched > >the Tesla screen display at 36.77 KWH. > > > > > > > >The car traveled from 72,553 to 72,414 or 139 miles. 139/36.77=3.78 miles > >per KWH or 264.5 watt hours per mile. With the car display at 244 watt > >hours per mile, that's a 7.7% efficiency loss through the onboard charger, > >so impressive aero efficiency as indicated on the InsideEVs website > >comparing all EVs. Conversions are probably less efficient do to poorer > >aero efficiency that takes an exponential hit at highway speeds. > > > > > > > >I was initially going to buy a Tesla-3 (now advertised at $37K) but said > *no > >towing* and the Y showed 3500 pounds of towing needed for towing my 5x8 > >trailer for solar panels/concrete/racking (solar volunteer club) and boat. > >Not sure why the Tesla-3 says no towing when it uses the *same* > drivetrain. > > > > > > > >BTW, I'm taking the advice of some and going to the dealer with the Bolt > to > >get the $1400 bait software 80% for 6200 miles - since the 2020 model > >battery issues are less than 1% (most occurred in previous years > 2017-2019). > > > > > > > > > > > >Have a renewable energy day, > > > > > > > >Mark > > > > > > > >Mark E. Hanson > > > >184 Vista Lane > > > >Fincastle, VA 24090 > > > >540-473-1248 phone & FAX, 540-816-0812 cell > > > >REEVA: community service RE & EV project club > > > >Website: www.REEVAdiy.org (See Project Gallery) > > > >UL Certified PV Installer > > > >My RE&EV Circuits: www.EVDL.org/lib/mh > > > >REEVA Demo: http://youtu.be/4kqWn2H-rA0 > > > > > > https://www.weatherlink.com/embeddablePage/show/a88920376f864ecabaed843dd89 > >75b8d/signature> Fincastle Solar Weather Station > > > > > > > > > > > >-------------- next part -------------- > >An HTML attachment was scrubbed... > >URL: > >http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20231026/70d11bc0/attachment.htm > > > >_______________________________________________ > >Address messages to ev@lists.evdl.org > >No other addresses in TO and CC fields > >HELP: http://www.evdl.org/help/ > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20231026/e076e773/attachment.htm > > > _______________________________________________ > Address messages to ev@lists.evdl.org > No other addresses in TO and CC fields > HELP: http://www.evdl.org/help/ > > -------------- next part -------------- An HTML attachment was scrubbed... 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