Efficiency of Leaf at Bike speed (~10 mph)

[theaveng]

This idea sprung into my head from another topic: Biking is the most-efficient way to travel (~700 MPGo). I think it's mainly because a bike moves slow, and therefore has very little wind resistance to overcome. QUESTION:

Has anyone ever tried driving the Leaf at a slow but steady speed of 10 mph? I imagine the MPGe would be almost as high as a bike... 500 MPGe or higher. (Perhaps a single seat EV like the Sparrow would be better-suited to this task.)

 

[TonyWilliams]

This idea sprung into my head from another topic: Biking is the most-efficient way to travel (~700 MPGo). I think it's mainly because a bike moves slow, and therefore has very little wind resistance to overcome. QUESTION:

Has anyone ever tried driving the Leaf at a slow but steady speed of 10 mph? I imagine the MPGe would be almost as high as a bike... 500 MPGe or higher. (Perhaps a single seat EV like the Sparrow would be better-suited to this task.)

Yes, I did this on a 2.5 mile loop at sea level on Fiesta Island in San Diego. About 12mph appears to be the peak economy, hence range. Yes, bicycles were outrunning me.

I'm trying to remember the specific data, and I think I remember 8.5 miles per kWh (118 WattHour per mile), for a theoretical range of 8.5 * 21 = 178 miles.

 

[theaveng]

If 33.7 is an accurate conversion factor, then 8.5 mi/kWh would be over 280 MPGe.

Hmmm. Somehow I thought it would be much higher than that. Maybe the car has too much rolling resistance (I inflate my tires to >40 to minimize that.)

 

[apvbguy]

If 33.7 is an accurate conversion factor, then 8.5 mi/kWh would be over 280 MPGe.

Hmmm. Somehow I thought it would be much higher than that. Maybe the car has too much rolling resistance (I inflate my tires to >40 to minimize that.)

and why would you want to go 10-15 MPH?

 

[TonyWilliams]

If 33.7 is an accurate conversion factor, then 8.5 mi/kWh would be over 280 MPGe.

Hmmm. Somehow I thought it would be much higher than that. Maybe the car has too much rolling resistance (I inflate my tires to >40 to minimize that.)

and why would you want to go 10-15 MPH?

When you're 3 miles from home, and the GOM is already flashing "---"

 

[theaveng]

and why would you want to go 10-15 MPH?

Why did I play Missile Command for hours as a kid? Answer: To see how high a score I could get. For fun/challenge.

Besides millions of people do 10-15 every day on their bike to work. They seem happy with that speed, so why can't a car driver do the same speed? It's still faster than my Amish neighbors go. ;-) (Also if it's the year 2030 and oil costs $1000/barrel, and electricity has also skyrocketed, then you would want to stretch your energy as much as possible.)

 

[LTLFTcomposite]

Tony, are you going to update your range chart to include that? Currently 35 is the lowest you have; I assumed that was because the range/efficiency dropped off below that.

 

[apvbguy]

and why would you want to go 10-15 MPH?

Why did I play Missile Command for hours as a kid? Answer: To see how high a score I could get. For fun/challenge.

Besides millions of people do 10-15 every day on their bike to work. They seem happy with that speed, so why can't a car driver do the same speed? It's still faster than my Amish neighbors go. ;-) (Also if it's the year 2030 and oil costs $1000/barrel, and electricity has also skyrocketed, then you would want to stretch your energy as much as possible.)

good for you, your bicycle riding friends and your amish neighbors whom are residing in a parallel reality.

If I wanted to travel at 15 MPH I too would adopt their choice of transport, but I and most other people in this world buy motor vehicles to speed their trips. The best response was to see how it does when you are close to home and the end is near

 

[iamwjh]

The question was asked about LEAF efficiency at ~10mph.
And fortunately, someone actually went out and tested the car to collect that data so we have an answer.

I think that is great!

Thank You.

It was a very specific question and a very specific answer and I don't see any reason why I should be rude about my response.

 

[apvbguy]

The question was asked about LEAF efficiency at ~10mph.
And fortunately, someone actually went out and tested the car to collect that data so we have an answer.

I think that is great!

Thank You.

It was a very specific question and a very specific answer and I don't see any reason why I should be rude about my response.

I am sorry if I appeared to be rude, I just couldn't wrap my head around the need to test the efficiency of the vehicle at 10 MPH, I suppose I am not up to your level of technical curiosity. test on

 

[LTLFTcomposite]

Rather than ask what is the efficiency at 10mph, isn't the more interesting question at what speed is efficiency maximized?

Climate control would be a big factor at very low speeds as you're spending a lot more time running heat/AC and not covering much ground while you're doing it.

 

[garsh]

Rather than ask what is the efficiency at 10mph, isn't the more interesting question at what speed is efficiency maximized?

TonyWilliams already answered that question earlier in this thread (12mph).

and why would you want to go 10-15 MPH?

When you're 3 miles from home, and the GOM is already flashing "---"

Been there, done that. Only I hit turtle mode, and I was still 2 miles from work! I went 12mph the rest of the way. I made it, parked the car, took a picture of the dash... and it shut down before I could turn it off.

 

[smkettner]

If I had only the LEAF to transport me and family from a disaster with no hope to recharge.... I would drive about 15 mph to the end of the battery then start walking. Actually I would probably set the cruise at 25 minimum.

Otherwise not interested in 10 hours at 15 mph challange for a Sunday afternoon.

 

[TonyWilliams]

Tony, are you going to update your range chart to include that? Currently 35 is the lowest you have; I assumed that was because the range/efficiency dropped off below that.

35mph is the lowest speed because most people aren't normally traveling below that speed, nor above 75mph (the car can do 94mph).

If you look at the 4th line down in the notes, you'll see this is already addressed.

 

[TonyWilliams]

Rather than ask what is the efficiency at 10mph, isn't the more interesting question at what speed is efficiency maximized?

Climate control would be a big factor at very low speeds as you're spending a lot more time running heat/AC and not covering much ground while you're doing it.

If you're attempting maximum range efficiency, by definition that means no cabin heating or cooling.

 

[TonyWilliams]

Rather than ask what is the efficiency at 10mph, isn't the more interesting question at what speed is efficiency maximized?

TonyWilliams already answered that question earlier in this thread (12mph).

and why would you want to go 10-15 MPH?

When you're 3 miles from home, and the GOM is already flashing "---"

Been there, done that. Only I hit turtle mode, and I was still 2 miles from work! I went 12mph the rest of the way. I made it, parked the car, took a picture of the dash... and it shut down before I could turn it off.

Yep, great job !!!! It's a real pain to maintain that slow speed, and you sure don't want to be accelerating and deaccelerating when you're trying to stretch range. The cruise control doesn't work below 24mph, so it's all on you at 12mph.

The best advice is, of course, all cabin climate control off and ECO for better modulation of the power to maintain that 12mph speed.

I did 1.8 miles once in Turtle mode, however much of that was down hill. I made it home!!!

 

[LakeLeaf]

and why would you want to go 10-15 MPH?

because your bike has a flat?

 

[LTLFTcomposite]

If you look at the 4th line down in the notes, you'll see this is already addressed.

TonyWilliams already answered that question earlier in this thread (12mph).

I need to work on my reading compression! :lol:

 

[garsh]

I need to work on my reading compression! :lol:

There's your problem. You're compressing your reading instead of comprehending it.

 

[Ingineer]

Just keeping the LEAF in ready mode, even if not driving, draws significant energy, so that's why there is a break-over point where going slower actually uses more power.

The minimum usually is still several hundred watts!

-Phil