MrDRMorgan said:CCIE said:MrDRMorgan said:It is my understanding that the 2015 Spark EV battery was changed to a lighter LG battery and the gearing was adjusted for better highway performance. Since I have both a 2014 and 2015 and have run both on the freeway, my experience is that the 2015 gives slightly better performance on the freeway.
It's the other way around. Because the 2015/16 have less power (400ft/lb vs 327lb/ft) they put lower gearing in. This improves acceleration, likely making up for the power loss. But, it means that the motor is spinning faster at any given vehicle speed.
Put another way, the 2014 had so much power that it could operate in "2nd gear" all the time. The 2015/16 operates in "1st gear" all the time.
So 2015/16 should be worse on the highway since the motor should be less efficient at higher RPM.
I found this which substantiates what you said:
"Of importance here is that GM had tested two different final drive ratios in the Spark EV. One, a 3.17 ratio, was eventually adopted for use in the production 2014 Spark EV. The other, a 3.87 ratio, will come standard on the 2015 Chevy Spark EV.
But that 3.87 ratio for the final drive is a significant alteration. The switch to 3.87 should increase city range for the Spark EV. However, in announcing that LG Chem will be responsible for the 2015 Spark EV battery (no longer is A123 involved), General Motors suggested that no MPGe or range ratings will change for 2015"
Here is the link to the full article: https://insideevs.com/2015-chevy-spark-ev-highlighting-changes/
Exactly!Planerench said:I assume by “performance” we are talking about kw per mile.
My guess would be: Absolutely nothing.Planerench said:I wonder what would happen if you simply switched planetary gear sets?
If the 2014 electrical installation didn’t know it had lower gearing the result would be increased torque supplied to the wheels. As far as I can tell.NORTON said:My guess would be: Absolutely nothing.Planerench said:I wonder what would happen if you simply switched planetary gear sets?
This spinning permanent magnet rotor is effected by the power flow in the stator.
Free Spinning fast or slow there may not be much difference in frictional drag.
This is not like an ICE where it's always pumping pistons and air and sucks a lot of power to do that in relation to RPM.
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