Better Efficiency blah blah blah

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

sthbeach

Well-known member
Joined
Aug 20, 2019
Messages
74
Here in Canada, my Leaf is set to metrics.
So I did some tests in the last week and all are based on approx 75 km runs one way to work. In an earlier post many of you responded to me with wind resistance stats at different speeds and about slowing down on the highway and I will get much better results and to that I say........NOPE, not that much better!
So after many runs at 120kph or 75mph my computer shows an average of approx 18.5 kw/100kms or about 5.4 kms per kw.
Driving at 105kph or 65mph my computer shows an average of approx 17.2kw/100kms or about 5.81 kms per kw.
The difference is .41 kms per kw x a safe usable 37 kw = A lousy 15.1 kms or just about 10 miles better.
So to this I say...... ,the stats that Nissan or maybe all EV vehicles give are really never designed for commuters and highway driving.
 
I think all EV manufacturers should have to mandatory state on the sticker "CITY Driving"
Or "stats based on city driving only".
At least then when commuters are doing some research before buying it becomes an eye opener that they can then look into further on one's own before purchasing.
 
Yes, I actually tried 3 different tests over the last 2 weeks. Resetting the trip after one way, resetting it after a round trip and also tried a rolling 2 day trip count.
 
That's aerodynamics for you.
Above 25 to 35mph air resistance becomes the major power eater.
Every time you double your speed your air resistance quadruples, then you are trying to go the same distance in half the time.
So you need 8 times the power to double speed.
On my leaf going from 55mph to 75mph nearly doubles power consumption. Going from around 10kw at 55mph to just under 20kw at 75mph, then add another 19mph to get 94mph and it takes nearly 40kw to maintain speed.

If you slow it down to around 55mph (really slow kph) you will like the range better.
 
sthbeach said:
Yes, I actually tried 3 different tests over the last 2 weeks. Resetting the trip after one way, resetting it after a round trip and also tried a rolling 2 day trip count.


Compare round trip at 75 mph Vs 65 mph, making sure to reset the meter each trip. You need at least 3 data points for each speed, and preferably tested as close together as possible to avoid weather changes. The main problem with one test is that wind cannot be controlled and it varies a lot from day to day.

I anticipate that you will see an ~ 13% improvement in miles/kWh.

It is also simple to calculate the Wh/mile savings at the lower speed since that is just aero drag which is equal to 0.5 * Rho * Frontal_area * CD * velocity * velocity (in Kg, meters, seconds to give a result in Newtons)

---
By the way, while you are blah blahing, take a few minutes to learn when to write kW and when to write kWh.
 
sthbeach said:
I think all EV manufacturers should have to mandatory state on the sticker "CITY Driving"
Or "stats based on city driving only".
At least then when commuters are doing some research before buying it becomes an eye opener that they can then look into further on one's own before purchasing.

The EPA test gives both highway and city ratings. Not sure what the problem is.
 
I will tell you what the problem is.........

Here in Ontario Canada, CBC had a company do a study on Highway 401 speeds and the actual test area is in my region where my commute is. They found that 85% of people travelled at a speed of 113-126 kph which is approx an average of 120 kph. The reason for the study is because they are thinking of increasing the highway speeds in Ontario to match that of British Columbia which are at 120 kph. They want to increase the highway speed because if 85% of drivers are not obeying anywhere close to the speed limit then it certainly is not a very effective limit. So these speed averages are nothing new, it has been this way for the last 25 years as I can remember it and like I said before, BC already has a higher speed limit. To my point now..... So why should a car company be able to market and sell a car where I live and say that it does 242 kms or even 200kms knowing that between weather (real bad for a solid 5 months a year) and real world driving speeds that their numbers are nowhere fucking close to the god damn sticker on the car!

Let me give you real world. So if I drive my highway commute in January weather at the average speed that 85% of people are driving at on my route, I am lucky if I pull off 140 KMS!
And that's the PROBLEM!!!
 
sthbeach said:
To my point now..... So why should a car company be able to market and sell a car where I live and say that it does 242 kms or even 200kms knowing that between weather (real bad for a solid 5 months a year) and real world driving speeds that their numbers are nowhere fucking close to the god damn sticker on the car!
Because there are 100s if not thousands of markets, compounded by driver differences. When it is -20C in Toronto it is 30C in Miami. When you are driving 120 kph, I am driving 110 kph and Grandma is driving 90 kph. When you are driving on level ground I am going up and down mountains. The Monroney sticker is best used to compare cars. If you want to see EPA results in your driving, drive like the test. It is more than a little foolish to presume that the test is a good predictor of sthb* on the 401.

It does no good to whine. You have to take some responsibility for your driving behavior and have a basic understanding of how your locale affects energy consumption.

Addendum: salty language removed
 
sthbeach said:
I will tell you what the problem is.........

Here in Ontario Canada, CBC had a company do a study on Highway 401 speeds and the actual test area is in my region where my commute is. They found that 85% of people travelled at a speed of 113-126 kph which is approx an average of 120 kph. The reason for the study is because they are thinking of increasing the highway speeds in Ontario to match that of British Columbia which are at 120 kph. They want to increase the highway speed because if 85% of drivers are not obeying anywhere close to the speed limit then it certainly is not a very effective limit. So these speed averages are nothing new, it has been this way for the last 25 years as I can remember it and like I said before, BC already has a higher speed limit. To my point now..... So why should a car company be able to market and sell a car where I live and say that it does 242 kms or even 200kms knowing that between weather (real bad for a solid 5 months a year) and real world driving speeds that their numbers are nowhere fucking close to the god damn sticker on the car!

Let me give you real world. So if I drive my highway commute in January weather at the average speed that 85% of people are driving at on my route, I am lucky if I pull off 140 KMS!
And that's the PROBLEM!!!

The test provides a baseline for comparison.

You're seriously proposing that the official government test agency test give special consideration and force manufacturers to accomodate the needs of law-breakers?

Again, the numbers are a basis for comparison and never have been warranted as a representation of your personal results if you don't match the test parameters.

There is a central truth to your complaint and it has everything to do with the "real world" -- the reality of aerodynamic drag is more apparent in an EV, because it is much more efficient to begin with. In an ICE we've become accustomed to the highway mileage being better than the city mileage. This is of course upside-down from the point of view of energy requirements. It's just that ICE engines are tuned for best economy at highway cruise and throw enough energy away at lower speeds to mask the effect. EVs get better City than HWY mileage because they don't throw energy away at lower speeds and stop-and-go driving.

But does a manufacturer need to go out of their way to explain what happens when you speed? I don't think so. If I choose to speed the consequences are my responsibility. And I have no truck with people who claim "they'll kill me if I try to do the speed limit". That is BS.
 
I have driven and worked on cars for over 25 years. I have owned over 60 cars since then. I think I know a thing or two about motor vehicles. I could drive the exact speed limit of the highway and in inclimate weather here I still won't due better than about 150 kms on my 242 km rated 1 year old vehicle. You guys like to throw out analogies to ICE vehicles, EPA and real world driving like it's all relative........ITS NOT!
You guys like analogies, ok.....that's like saying I go and buy a new ICE vehicle that says 25 mpg highway and then I drive it on my commute to work doing 120 kph in the dead of winter and I'm getting 15mpg! No, because I probably won't do any worse than 20mpg.
No even half educated buyer thinks they will only be getting 150kms on their winter commute in their new 2018 Nissan Leaf when they are signing on the dotted line.
 
No, they will lie and tell you what you want to hear to sell their cars. And this is a big reason why after 10 years the EV market only counts for 3.5% in North America.
You guys are saying it, but you just don't hear yourselves.
Ok, so EV's suck on the highway - Fact
So, therefore EV's suck for alot of commuters.
So next year I plan on taking a trip to Myrtle Beach with my family, it's a 1600 kilometer trip....hey, I have awesome idea, let's take the Leaf and we'll only have to stop and charge 9 TIMES......EACH WAY!!!
Oh no honey, let's take my Tesla Model 3 that way we only have to stop and charge 5 times each way!
Oh, but come on honey, even after all the incentives and discounts it's still only costing 1.5 times that of its ICE counterpart.
EV's.....not for everyone.... actually not for most!!!! LOL
Come talk to me in 5-10 more years.....lmao
 
sthbeach said:
...No even half educated buyer thinks they will only be getting 150kms on their winter commute in their new 2018 Nissan Leaf when they are signing on the dotted line.

I understood the pros and cons of EV driving when I got my first LEAF in 2011. It's a totally different technology; marching into a dealership with preconceived notions and no reasearch makes no sense in this day and age, for ANY car, much less if spending that much on a tech you are not familiar with. I can meet or beat the EPA numbers any time I care to, BTW. Because I understand the reality of driving an EV and I can put my ego to one side.
 
There is no Ego.....
I have said it in previous posts, come and drive on the 401 where I live and you will quickly realize why the average speed is 120 kph.
If you drive 105-110, good luck surviving with the 18 wheelers.....it's just not a safe speed.
If you adjust your driving even further like the wise one, Sagebrush, advises and drive 90-100 kph.....heh, on the 401, I would strongly advise against it and go as far as saying that 120 kph is the safest speed compared to the above mentioned.
I suggest that the California dreamers stay put in the land of the liberals and palm trees and stop making ignorant comments.
 
sthbeach said:
There is no Ego.....
I have said it in previous posts, come and drive on the 401 where I live and you will quickly realize why the average speed is 120 kph.
If you drive 105-110, good luck surviving with the 18 wheelers.....it's just not a safe speed.

I've driven in most States and six Provinces. Saying you can't possibly be safe at the maximum posted speed is self-delusion. I've heard it many times and frequently in regards to roads familiar to me. I've never found it to be the case. Believe me there's no special force at work in your neck of the woods.
 
sthbeach said:
If you adjust your driving even further like the wise one, Sagebrush, advises and drive 90-100 kph....
No such advice given. I tried to explain to you with simple examples why the EPA test is not sthb* on the 401.
 
sthbeach said:
I suggest that the California dreamers stay put in the land of the liberals and palm trees and stop making ignorant comments.
Why is it that those that pull out the 'liberal' card are the ones who have difficulty with basic physics ?
 
Nubo said:
Again, the numbers are a basis for comparison and never have been warranted as a representation of your personal results if you don't match the test parameters.

This
 
I empathize with the Original Poster. It is unfortunate that your purchase does not meet your expectations... Perhaps there is some defect in the battery or elsewhere.. Maybe Nissan would be able to determine this..

On the other hand, an EV like the Leaf is a different animal than a gas car. I see it like the difference between two types of ships.. The Leaf is not like a cruise ship or a speed boat. I see it more like a sailboat. It is super efficient and it is powered very humbly. Traveling in it is like a liberating experience, not an event of the daily grind. When I drive mine, I am constantly (still after 5 years) in awe that I am driving thousands of miles without a drop of petroleum, and powered by my house's lighting, like my air conditioner or TV.

I also disagree that one MUST drive at 75MPH to be safe (in any country) if the posted speed limit is 55-60. Perhaps young people are moved by group peer pressure to drive like all of the others for fear of not being liked.. If you look at it logically, what inconvenience do you pose if you are going slower than the fast traffic? Those that are passing you must change lanes-- for a total of 10 seconds work.. Meanwhile, I will go the speed that I WANT.
 
Back
Top