Quote:
Originally Posted by Isaac Zachary
This is physics. Not magic. I don't second guess physics. Nothing in the thesis proves that a heavier BEV is more efficient overall.
In fact it states in figure 4.1 that the small BEV uses the least amount of energy per distance.
It also states on page 26 that
This is exactly what I am getting at. The small BEV uses less energy overall. But it seems less efficient in urban driving due to a smaller mass that results in a lower accelerating kinetic energy.
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Returning to the beginning:
1) When Oil Pan 4 mentioned weight reduction of the Tesla Model 3, my 'little gray cells' flashed to the 2015 thesis.
2) Gustafsson & Johansson had said that the 'small' Volvo V40 SUV BEV demonstrated 'strange' behavior with respect to European test cycle constraints and proportionally-weighted urban performance, having to do with regenerative braking, and mass.
3) The Tesla Model 3 is the 'small' Tesla. I threw a caution flag out on the field.
4) And we're having a conversation about it.
5) The physics is quite clear to me.
6) The thesis authors provide the caveats, conditions, constraints, and boundaries for their argument.
7) I'm limiting my participation to only the operational parameters, as laid out by the original authors.
8) Those parameters are specifically limited to a 'small', Volvo V40 SUV BEV, in a CITY cycle segment of the New European Driving Cycle ( NEDC ).
9) It is a fact, that since 2015, Not only did Volvo increase the mass of the V40 to that of the 'mid-sized' S80, they exceeded the mass of the 'full-sized' XC90 by another 28-kg, arriving at a 593-kg ( 1,307- LB ) mass increase. Delta- 37.7%.
10) The ' such a small' ( Mark Rechtin, MOTOR TREND ) Volvo outruns it's ICE stablemate, and has 316% higher 'fuel' economy.
11) It has ' Strong regenerative braking' ( Duncan Brady, MOTOR TREND ).
12) All automakers are held to official testing protocols, and internationally, combined testing results are proportionately-weighted towards 'CITY/Urban' performance.
13) Everyone is free to run all the calculations and compare the differences.
14) Everyone is free to explore ULRR tire technology and ponder what options Volvo might have with respect to any RR increase to additional mass, over all the testing cycles.
15) Everyone is free to calculate the delta-Inertia Resistance.
16) Everyone is free to calculate the delta-energy recovery to the Volvo, via regenerative braking.
17) I should have my math finished by tomorrow. Storm weather is predicted for the time I'd be walking here in the morning, so I elected to come today, losing a day for calculations.