TimLee
Well-known member
When did Nissan lose their mind :?:
Lying about range by eliminating 80% charging :?:
"Madness!... Madness!"
Lying about range by eliminating 80% charging :?:
"Madness!... Madness!"
LeftieBiker said:That graph would seem to indicate that a two speed transmission, with a low gear for city driving, would help significantly by reducing 'lugging' of the drive motor. It would help to see a graph of consumption vs speed as well. A simple two-speed, low-friction transaxle, combined with more sophisticated software management of power consumption, could still add range. In that case the higher gear ratio could also be somewhat higher, allowing less consumption at freeway (65-75MPH) speeds. So instead of having a compromise sweet spot of about 45MPH, you'd have one at about 30MPH and one at, hopefully, 55-60MPH...
LeftieBiker said:Tesla was building a performance car. I think a 2 speed transaxle could handle the Leaf's detuned motor, with the right Low ratio.
DaveinOlyWA said:LeftieBiker said:Tesla was building a performance car. I think a 2 speed transaxle could handle the Leaf's detuned motor, with the right Low ratio.
correct answer to the wrong question. maybe we should consider that if not building a performance car, multiple gears are not necessary in an EV. gearing increases speed performance, not range performance.
You can't go from 84 to 100 by minor tweaks.LeftieBiker said:I'm fairly sure they could tweak the drivetrain to give the car an actual 100 mile range, by limiting both acceleration and top speed to reasonable figures, and keeping the motor near peak efficiency at most speeds.
evnow said:You can't go from 84 to 100 by minor tweaks.LeftieBiker said:I'm fairly sure they could tweak the drivetrain to give the car an actual 100 mile range, by limiting both acceleration and top speed to reasonable figures, and keeping the motor near peak efficiency at most speeds.
Acceleration and top speed don't matter much in standardized cycles.
There just isn't much room for cost effective improvement when the lowest efficiency point is already at 84% or greater.LeftieBiker said:If consumption can be reduced at the two most common speeds driven, range will improve by more than a tiny bit.
LeftieBiker said:DaveinOlyWA said:LeftieBiker said:Tesla was building a performance car. I think a 2 speed transaxle could handle the Leaf's detuned motor, with the right Low ratio.
correct answer to the wrong question. maybe we should consider that if not building a performance car, multiple gears are not necessary in an EV. gearing increases speed performance, not range performance.
Gearing can do either, or both - that's what ratio optimization is about. If the Leaf is, as it appears from the graph, wasting power at both low speeds and freeway speeds, then designing the transmission to provide optimum motor speed at those two points would help both low speed acceleration and overall range, if the driver exercises restraint.
LeftieBiker said:DaveinOlyWA said:LeftieBiker said:Tesla was building a performance car. I think a 2 speed transaxle could handle the Leaf's detuned motor, with the right Low ratio.
correct answer to the wrong question. maybe we should consider that if not building a performance car, multiple gears are not necessary in an EV. gearing increases speed performance, not range performance.
Gearing can do either, or both - that's what ratio optimization is about. If the Leaf is, as it appears from the graph, wasting power at both low speeds and freeway speeds, then designing the transmission to provide optimum motor speed at those two points would help both low speed acceleration and overall range, if the driver exercises restraint.
Since most BEVs are limited range cars best suited for shorter commutes at lower speeds, doing away with a transmission makes sense. But for high speed highway driving, a transmission may be less expensive, lighter and consume less space as well as being quieter than a bigger battery pack.davidcary said:Nissan and Tesla and I think every other EV maker has concluded that a single speed is all an EV needs. Even Tesla with top speed of 130 still went with a "1 speed".
So they are wrong and you are right?
NYLEAF said:Apparently, in survey-speak, "Would you like an EPA range of ~150 miles for an extra ~$5000?" actually means "Would you like a different shade of blue?"
Tesla started out with a two speed gear reduction in the Roadster and quickly changed it over to a single speed.LeftieBiker said:Nissan obviously wasn't very concerned with drag when they designed the Leaf, and could easily reduce it even with a two speed transaxle. Friction increase would be tiny. Weight increase also small. Electric motors with no transmission are great for limited speed ranges. When you want high efficiency over a 10-95MPH spread, you're stretching it too far. You can have the last word.
And the reason they did so was mentioned in my post three above yours, and Nubo's post back one page.jelloslug said:Tesla started out with a two speed gear reduction in the Roadster and quickly changed it over to a single speed.LeftieBiker said:Nissan obviously wasn't very concerned with drag when they designed the Leaf, and could easily reduce it even with a two speed transaxle. Friction increase would be tiny. Weight increase also small. Electric motors with no transmission are great for limited speed ranges. When you want high efficiency over a 10-95MPH spread, you're stretching it too far. You can have the last word.
"Actual 100 mile" makes no sense. Actual for who - in what conditions etc etc ?LeftieBiker said:I wrote "actual 100 mile" not "EPA rated 100 mile." If consumption can be reduced at the two most common speeds driven, range will improve by more than a tiny bit.
davidcary said:Nissan and Tesla and I think every other EV maker has concluded that a single speed is all an EV needs. Even Tesla with top speed of 130 still went with a "1 speed".
So they are wrong and you are right?
evnow said:"Actual 100 mile" makes no sense. Actual for who - in what conditions etc etc ?LeftieBiker said:I wrote "actual 100 mile" not "EPA rated 100 mile." If consumption can be reduced at the two most common speeds driven, range will improve by more than a tiny bit.
Heat pump was a good example of "actual" reduction in consumption without affecting EPA numbers, BTW.
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