Efficiency Versus Speed

[DunanyDon]

I was curious to know if there was a particular speed that delivered the highest efficiency, as there is for an ICE, so I drove over the same section of road at 30, 40, 50, 60 and 70 km/hour. It was very clear that the faster I went, the less efficient the Leaf was. This would be true except if you were just barely moving along, where the power drawn by the lights, computers, heating or A/C, etc. would exceed the power drawn by the traction motor.

 

[nlspace]

So where did you find it worked better, around 60 ?

Are you looking at km/kwh as the metric?

 

[Oostenrijker]

An average speed of 50km/h is the most efficient, is my personal conclusion. If you use Herewego and shortest route settings, then you get a combination of some highways and inner roads.

The consumption increases, once your average speed is above 50km/h: but if you drive on a highway and stay behind a truck, then you can drive almost as efficient. As when driving 50km/h.

All is also depending how good you can regenerate: it isn't about regenerating the most energy, but trying to cruise a long as possible in D mode. While gaining little energy back. Because if you do E-Pedal or drive always in B mode, then actually you will drive less efficiently.

Cruising is still more efficiently, then regenerating to the max: only I wouldn't advise to shift to neutral, while it's possible. It's really dangerous.

 

[RNeil]

Air resistance is proportional to the speed squared. The faster you go, the less efficient it is.

ICE cars also have this issue. But their engines are much less efficient at low power. They even consume power standing still. That is why their highway mileage is better than their city mileage. Our electric motors are as efficient at low power.

 

[nlspace]

Yes, Air resistance is proportional to speed squared (v^2), but the power to overcome it goes up by speed cubed (v^3).

 

[GaleHawkins]

I find 45 mph to be the functional Best speed for a range extension but you got to be careful not getting rear-ended. For hyper miling, it drops down to about 20 mph to be ideal.

 

[MikeinPA]

 

[DougWantsALeaf]

that's a great graph

 

[DougWantsALeaf]

Finally did a small efficiency test with the eRange tires at 55mph.

 

[FrancoVecchi]

I foud this graph.... the best speed for a low consuption is 40 Km/h

 

[DougWantsALeaf]

Thanks

 

[Bombastinator2]

The old old thing was 45mph. That’s why the model T maxed out at 45. Might be specific to a model T though. Also May not take aerodynamics into account. It’s higher than 40kph which implies there is something off with it.

 

[Toby]

From a practical point of view there are two steps to good efficiency.

1. pump up your tires to 40psi.
2. drive at or below the posted speed limit.

 

[Araknai]

This is for the 24kwh pack, yes?

Considering the most "normal" drive lines up with 70-80 miles of range.

 

[Bombastinator2]

From a practical point of view there are two steps to good efficiency.

1. pump up your tires to 40psi.
2. drive at or below the posted speed limit.

I suggested 40 psi to a mechanic and he said it would screw up my tire wear

 

[Araknai]

I suggested 40 psi to a mechanic and he said it would screw up my tire wear

People say that, but doesn't match my experience whatsoever. I've been doing 42 psi since I got my Leaf in 2019; 40k miles between a set of All Seasons for the summer and Snow tires for the winter. Neither set showing any signs of needing replacement soon.

 

[Learjet]

40 psi = great wear on my last set of tires. You have to understand how much the vehicle weights...etc before you give a generic answer.

 

[cwerdna]

Tony Williams put together https://mynissanleaf.com/threads/range-chart.4295/ ages ago.

He also mentions in the 100% chart that the speed for max range is 12 mph. Might be easier to see on page 1 of https://www.dropbox.com/s/d1d9htu2bqoaej8/LEAFrangeChartVersion7G100.pdf?dl=0.

 

[Bombastinator2]

People say that, but doesn't match my experience whatsoever. I've been doing 42 psi since I got my Leaf in 2019; 40k miles between a set of All Seasons for the summer and Snow tires for the winter. Neither set showing any signs of needing replacement soon.

They’re not wearing more in the middle than at the sides?

 

[Araknai]

They’re not wearing more in the middle than at the sides?

Nope, not yet; just had to go make sure. Totally even wear and decent amount of tread left.
Sentury Tourings and I'd guess they're at around 28k miles on em.