sthbeach
Posts: 70
Joined: Tue Aug 20, 2019 4:49 pm
Delivery Date: 16 Aug 2019
Leaf Number: 312576

Better Efficiency blah blah blah

Tue Sep 10, 2019 8:00 am

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.
Last edited by sthbeach on Tue Sep 10, 2019 8:15 am, edited 1 time in total.

sthbeach
Posts: 70
Joined: Tue Aug 20, 2019 4:49 pm
Delivery Date: 16 Aug 2019
Leaf Number: 312576

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 8:06 am

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.

SageBrush
Posts: 4907
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 8:13 am

Are you resettting the trip meter ?
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

sthbeach
Posts: 70
Joined: Tue Aug 20, 2019 4:49 pm
Delivery Date: 16 Aug 2019
Leaf Number: 312576

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 8:26 am

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.

Oilpan4
Gold Member
Posts: 853
Joined: Wed Jan 09, 2019 10:51 pm
Delivery Date: 10 May 2018
Leaf Number: 004270

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 1:53 pm

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.
2011 white SL leaf with 2014 batt.
Chargers: Panasonic brick moded for 240v, duosida 16a 240v and a 10kw setec portable CHAdeMO
Location: 88103

SageBrush
Posts: 4907
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 2:41 pm

sthbeach wrote:
Tue Sep 10, 2019 8:26 am
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.
Last edited by SageBrush on Tue Sep 10, 2019 6:03 pm, edited 2 times in total.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

User avatar
Nubo
Posts: 5390
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 5:53 pm

sthbeach wrote:
Tue Sep 10, 2019 8:06 am
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 noticed you're still working with polymers.

sthbeach
Posts: 70
Joined: Tue Aug 20, 2019 4:49 pm
Delivery Date: 16 Aug 2019
Leaf Number: 312576

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 8:12 pm

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!!!

SageBrush
Posts: 4907
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 8:46 pm

sthbeach wrote:
Tue Sep 10, 2019 8:12 pm
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
Last edited by SageBrush on Wed Sep 11, 2019 4:07 am, edited 1 time in total.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

User avatar
Nubo
Posts: 5390
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: Better Efficiency blah blah blah

Tue Sep 10, 2019 9:32 pm

sthbeach wrote:
Tue Sep 10, 2019 8:12 pm
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 noticed you're still working with polymers.

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