Prime 0-60 :15 sec in EV mode

Toyota says it's faster to 40 in Ev than in Hv. A plot posted earlier shows that as well. I have a very hard time believing the 15 second number is correct. It'll be under 5 seconds to 40.

 

Don't forget that they were driving pre-Produktion models !
I don't believe 15 sec. 0-60 either !
Under 5 sec. to 40 and then about 10.2 sec. to 60 ?
Just think about it,doesn't make sense !

 

2017 Prius Prime First Drive: Best Prius Ever | Page 4 | PriusChat

 

I'll believe Toyota over a journalist.

 

That chart was from a Toyota video.

The dual-motor acceleration mode is reported to be only available when there is sufficient state of battery charge. If he was below that limit when he did his testing, he could have been in single-motor acceleration mode and not known it. I think Danny said it was definitely faster off the line in Ev than in Hv.

 

"The Prime was brisk at higher speeds, and it positively spit away from rest." (Talking about Ev mode, based on context).

2017 Toyota Prius Prime First Drive Review - Motor Trend

 

Electric motors have different power and torque curves than an ICE. They produce max torque at zero rpm. From a stop they can be very quick in the beginning. Anecdotal reports had the gen2 beating BMWs and Porsches to 20mph. Past zero rpms, the torque output drops. I haven't seen a torque curve for an AC motor, but a basic DC one will have torque drop in a straight slope until max rpms are reached.

So has motor and car speed increases, the acceleration rate decreases. This means a 0 to 40 in 5 seconds, and then another 10 seconds to reach 60 is feasible, though I wouldn't discount the OP review might not have been in dual motor mode.This is essentially the opposite of an ICE where acceleration is slow at first until engine speed reaches peak torque, and then the car takes off.

 

An AC motor will have a torque limit based on its current limit. A PM motor will limit this current based on magnet "strength" to avoid demagnetizing the magnets (with a safety factor since that also goes strongly with magnet temperature). That torque will be available over a wide range of speeds unless limited by upstream components like the power electronics or power source.

Since power at zero speed is zero, full torque is certainly available at zero. As speed increases, power increases at constant torque (Power = torque * speed) so torque can remain constant for a while. At some point, either the PE or battery will be current limited (PE) or power limited (battery), and torque will have to drop as speed increases to keep power constant.

Acceleration goes with torque (minus drag force).

 

It isn't additive in the way you are implying.

 

Danny said it was faster 0-40 in Ev mode than it is in Hv mode. This is consistent with Toyota's acceleration graph. He also said it was slower 40-60 in Ev mode than Hv mode. This is not consistent with Toyota's acceleration graph.

I've got a 6.8 second car, and an '04 Prius (around 10 seconds). I've never once had trouble merging or passing in either one. The only power troubles I've ever had with the Prius is once the battery has fully drained on a mountain pass. There's usually sufficient power to maintain speed, but not enough to accelerate. If someone slows you down, it takes a long time to get back up to speed.

 

Did you do the math?

KE = 1/2 * M * V^2.

V = 60mph = 26.8m/s
M = 3500lbs = 1,591kg

KE = 1/2 * 1,591 * 26.8^2 = 571kJ

90HP = 67.1kW

571kJ / 67kW = 8.5 seconds

It won't be that fast because it won't reach maximum power at zero speed (that would require infinite torque) and there is drag to account for (minor on a run to 60). Still, 10-11 seconds is about right.

FYI, 15 seconds to 60 in that car is 38kW or 51HP average.

 

That Toyota-supplied acceleration graph is something I went through the trouble of integrating.

The results were: Ev mode 0-60, 7.5 seconds, Hv mode 0-60, 10.5 seconds.

Maybe that graph is a wrong, or just a cartoon illustration, I don't know.