0-60 acceleration

[TomT]

Actually, the 500 will be getting here in the U.S. is pretty quick and a really cool little car. The numbers I have seen show it to be about a second quicker to 60 (8.8) than the Leaf (10.0) and a very good handler. And with the Multiair Electro-Hydraulic Valve-Timing System engine (a very cool technology), it gets great mileage

A friend is trying to decide between a Fiat 500 and a Nissan 370Z. I'm trying to convince him to get the Fiat so I'll have someone to drag race in my Leaf. More fun to drive a slow car fast, than a fast car slow.

 

[Herm]

The LEAF has been optimized for city driving, probably around a 35mph average speed.. yes it can do hwy speeds but the range drops quickly. The motor design and single gear rate were chosen for its intended mission. A solution for this is to use a 2 speed transmission but I think that would be a step back in the simplicity and reliability department. The efficiency probably peaks around 35mph, perhaps accounting for the range hit at hwy speeds (plus drag etc).

 

[EVDRIVER]

The LEAF has been optimized for city driving, probably around a 35mph average speed.. yes it can do hwy speeds but the range drops quickly. The motor design and single gear rate were chosen for its intended mission. A solution for this is to use a 2 speed transmission but I think that would be a step back in the simplicity and reliability department. The efficiency probably peaks around 35mph, perhaps accounting for the range hit at hwy speeds (plus drag etc).

If the LEAF were optimized for city driving as an EV it would not have a top speed of 90 MPH. City optimized EVs have lower top speeds and lower gear ratios for low speed driving, ie the THINK City. Using a two-speed on an EV like this is pointless. Highway is all about exponential wind drag.

 

[Herm]

If the LEAF were optimized for city driving as an EV it would not have a top speed of 90 MPH. City optimized EVs have lower top speeds and lower gear ratios for low speed driving, ie the THINK City. Using a two-speed on an EV like this is pointless. Highway is all about exponential wind drag.

The motor design and gearing were optimized for the LA4 cycle, I bet.. and my bet is just as valid as yours.. that it tops out at 90mph is just where the cards fell, there is probably a 10% drop in motor efficiency at those rpm levels, plus all the added drag of course. Go look at an EV motor efficiency curve.. at what rpm point would you have optimized it for?.. probably the same LA4 cycle.

 

[EVDRIVER]

If the LEAF were optimized for city driving as an EV it would not have a top speed of 90 MPH. City optimized EVs have lower top speeds and lower gear ratios for low speed driving, ie the THINK City. Using a two-speed on an EV like this is pointless. Highway is all about exponential wind drag.

The motor design and gearing were optimized for the LA4 cycle, I bet.. and my bet is just as valid as yours.. that it tops out at 90mph is just where the cards fell, there is probably a 10% drop in motor efficiency at those rpm levels, plus all the added drag of course. Go look at an EV motor efficiency curve.. at what rpm point would you have optimized it for?.. probably the same LA4 cycle.

They would not optimize for a drive cycle they would design what is best for the utility of the vehicle. Mixed use speeds, weight, etc. I think the motor is sub 13K RPM. I have owned and built many of EVs and I the LEAF was designed to carry loads AND have a higher average speed than a city EV, much higher. This is not just about gearing since they have used a lower HP motor with a higher torque level allowing a higher gear compromise and the ability to carry large loads. The motor look like a larger diameter making it more efficient. A larger motor produces more torque the a smaller motor at a lower current draw.

 

[evnow]

The LEAF has been optimized for city driving, probably around a 35mph average speed.. yes it can do hwy speeds but the range drops quickly.

The range drops not because of efficiency drop of the drivetrain but because of the drag. I doubt there is much of a difference between 35 mph and 65 mph efficiency.

 

[derekjsmith]

The LEAF has been optimized for city driving, probably around a 35mph average speed.. yes it can do hwy speeds but the range drops quickly.

The range drops not because of efficiency drop of the drivetrain but because of the drag. I doubt there is much of a difference between 35 mph and 65 mph efficiency.

Sounds like dyno testing time :shock:

 

[EVDRIVER]

It is easy to experiment on an EV with a proper kw meter and a manual transmission. I had a conversion were I used to experiment with various efficiencies based on speed and gear ratio.

 

[onthewind]

Another loss at higher speed is just the internal resistance of the electric path (batteries and control).
High speed = waste heat in batteries, control, motor. The extra power needed to overcome drag
makes this worse.

Jim C.

 

[aarond12]

Sounds like dyno testing time :shock:

Already done for you: http://www.mynissanleaf.com/viewtopic.php?f=27&t=5323