# Efficient driving



## piotrsko (Dec 9, 2007)

more motor rpm is less current (generally). verify on your set up.

105 mi? either you are cruising the big island or making 4 passes on Oahu.


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## Guest (Aug 12, 2011)

Keep the rpm's up and stay in 2nd or 3rd if you can. That is where you will do your best at low speeds. But yes, keep the rpms up. Not over revving but keep them up. It's not an ICE


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## spdas (Nov 28, 2009)

piotrsko said:


> more motor rpm is less current (generally). verify on your set up.
> 
> 105 mi? either you are cruising the big island or making 4 passes on Oahu.


It adds up here even on Oahu. One pass starting Kapolei/Barbers Point to Haleiwa/North Shore to Kaneohe and back over the H-3 to Kapolei. But now maybe not this weekend

Francis


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## GerhardRP (Nov 17, 2009)

spdas said:


> Ok I have the mindset that if you want to drive the most efficiently in an ICE and cruise at say 45mph, shift into the highest gear asap and cruise. But is that true with an EV? If I want to cruise with the traffic, should I stay in say 3rd and keep 3500rpm or go up to 4 or 5th to lower the rpm to 2000? I am going around 105 miles this weekend which is stretching my range. I am using a warp9/zilla/5speed/Yaris/45x180ah litho's
> 
> Francis


Have you taken any zilla data dumps from the system? It might be possible to get a real answer with real data.
Gerhard


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## spdas (Nov 28, 2009)

GerhardRP said:


> Have you taken any zilla data dumps from the system? It might be possible to get a real answer with real data.
> Gerhard


In a nutshell. How do you do a Zilla dump. I have ZillaConfig and Hyperterm on a netbook in the EV. What shud I do? thanks
Francis


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## Bowser330 (Jun 15, 2008)

gottdi said:


> Keep the rpm's up and stay in 2nd or 3rd if you can. That is where you will do your best at low speeds. But yes, keep the rpms up. Not over revving but keep them up. It's not an ICE


you also have to worry about the transmission right? The transmission wasn't designed to run @ say, 4000rpm, for long periods of time...will it be able to handle that?


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## GerhardRP (Nov 17, 2009)

spdas said:


> In a nutshell. How do you do a Zilla dump. I have ZillaConfig and Hyperterm on a netbook in the EV. What shud I do? thanks
> Francis


I have not done it myself because I don't yet have an EV. Maybe Mike Willmon can give you some guidance.
Gerhard


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## spdas (Nov 28, 2009)

Zilla dump. Are you referring to DAQ mode? (data aquisition)

Francis


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## spdas (Nov 28, 2009)

gottdi said:


> Keep the rpm's up and stay in 2nd or 3rd if you can. That is where you will do your best at low speeds. But yes, keep the rpms up. Not over revving but keep them up. It's not an ICE


So dealing with RPM's I wonder how EV'ers are installing with direct single speed drive then. Mine in 1-2 is tire burnout time and can overrev quickly. When I start in 4-5 it is very sluggish. I can't imagine driving a single speed or direct drive

Francis


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## GerhardRP (Nov 17, 2009)

spdas said:


> Zilla dump. Are you referring to DAQ mode? (data aquisition)
> 
> Francis


 Yes, I think I want DAQ4 mode. They say things change, so we should check with Cafe Electric.
Gerhard


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## gsmith191145 (May 1, 2011)

spdas said:


> So dealing with RPM's I wonder how EV'ers are installing with direct single speed drive then. Mine in 1-2 is tire burnout time and can overrev quickly. When I start in 4-5 it is very sluggish. I can't imagine driving a single speed or direct drive
> 
> Francis


I will try not to over complicate my answer.

In a direct drive system you are going to give up top speed and low end acceleration. 

A Transmission is geared to keep the motor in the "power band"

Tires and differential gears play a part in this also. 

Just keeping it simple. Not saying it will be a slug, just saying that you lose a little bit on each end.


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## spdas (Nov 28, 2009)

I guess my perspective is that running an EV, since electric motors have torque all the way from 0 on up, that it does not mean a gearbox is not necessary. You can make a simpler EV by using a direct drive, but it would be even better to have a full range of indirect gears to keep the motor at the 3500rpm "sweet spot". If you are driving mostly in town you will not need the range as much, but if you are operating in stop and go traffic, and freeway speeds, a gearbox is essential. But again if driving 0-60mph in 18 seconds is acceptable then that is OK too.

Francis


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## Guest (Aug 13, 2011)

Just drive like you normally do. Accept the distances you get and enjoy your ride. I do.


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## Bowser330 (Jun 15, 2008)

gottdi said:


> Just drive like you normally do. Accept the distances you get and enjoy your ride. I do.


of course you do, in your cool ass leaf! haha

kidding


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## spdas (Nov 28, 2009)

Just did 100.4 miles on at charge: 

Data:
50% driving freeway at 50-55mph
50% driving around the island at 40 mph
10 miles was uphill @ 3% to 6% grade

Total Miles 100.4
AH Used 133
WH Used 18695
AVG W/Mile 186.21

45 calb cells @ 198ah @ 3.2v each
28512 KWH pack

153.12 miles at 100% discharge. Of course I would be needing to buy new cells at that rate.

At this 100 mile rate cells were sagging considerably more, so I don't really know how many more amps are left, and I don't feel like experimenting to find out. Voltage at throttle let off 3.22v and at 50mph the cells sagged to 3.06v at about the 90 mile point on the freeway.


francis


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## Guest (Sep 1, 2011)

Hey, thats pretty impressive mileage combined. It's like my Leaf. Stick in the 85 to 90 mile range and your cells will be happy. Thats pretty darn good. Glad to hear things are doing well. 

Pete

The Leaf is a 24kw pack but it is also not the same chemistry as yours. So with your size pack and chemistry your doing damn good. 

Do you have peppy performance?


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## Guest (Sep 1, 2011)

> Voltage at throttle let off 3.22v and at 50mph the cells sagged to 3.06v


That is fine. I sagged my cells to 2 volts and a few times sagged them to below 2 volts each. Did not keep them in that zone long. When you sag under load it is not the same as at static voltage. If your at a static voltage of 3.0 volts your nearly at the end. Time to charge up. Sagging some into the 2.8 volt range will happen. But seeing your results says you may have some left. But when the sagging starts getting lower for the same speeds then your coming into the end and time to charge. So you said the sagging was starting to go deeper. I'd say your nearing your safe end of charge. Time to charge up. 90 miles combined is good.


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## spdas (Nov 28, 2009)

Yes it is quite peppy, (up to 2700rpm where the amps take a dive from 670amps to 200amps @3300rpm). Can't figure the problem.

But today I was babying the throttle, so I think 85-90 miles normal semi aggressive driving will be the sweet spot. 
I still have a couple of tricks for aero at freeway speed.

1: go to 175/65/15 "quiet" good rr tires from my 195/55/15's
2: skin the underside as there are a few rough edges from motor on back as well as there is a humongous air-dam trapping air inside the rear bumper.
I will do each of the above changes in a week or two after I firmly establish the current range. 

I am quite happy with it, as it is basically new 2007 with 8,484 miles and tight and surprisingly smooth ride.

But BTW the speedo is over 6% so i guess the odometer is off too, with these tires. The radar displays show 36mph and I was going 38. 

francis


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## spdas (Nov 28, 2009)

I need to check my balance now. Will test the bottom and adjust cells then charge them up and see where they land. (since I had the 5 cells fail a couple months ago, actually 1 is dead). I set up more solar panels on my charge controller, so Now I can charge 17-20kwh in one good day of sunshine.

Francis


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## Guest (Sep 1, 2011)

What controller again are you using and what settable functions does it have?

Pete


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## spdas (Nov 28, 2009)

I have 24 x 200 watt panels hooked up to an Outback 60 (I am off the grid). I charge at 80v and up to 50amps in strong sun. I have it adjusted for bulk 80v and float 80v @ one hour. So I charge a 1/2 pack at a time and they charge identically. The controller rams the voltage from say 72 dead pack voltage to 80v (3.48v) and once it hits 80v it goes into absorb mode for one hour (time is counted as absorb as long as the voltage is 80v, less than 80v is not counted in the one hour time). One hour seems about right as during that hour the amps will taper all the way down to 0.01amps. Since I have the "float" set to 80v as well it basically is not used except maybe giving 1-2 amp near the end of charge before it drops all the way to 0.01amps.


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## Guest (Sep 1, 2011)

Controller, not charger.


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## Ziggythewiz (May 16, 2010)

gottdi said:


> Controller, not charger.


*Motor* controller, not charge controller


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## Guest (Sep 1, 2011)

Yes, I have a Synkromotive controller. What is yours and what are the programmable parameters. 

Pete


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## spdas (Nov 28, 2009)

Ahhhh, controller. I have Zilla 1 HV and warp9. In the car i have a netbook with zillaconfig program, displaying Volts (bat+motor) Amps (bat+motor) temp, AH, KWH, Tach.

francis


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## Guest (Sep 2, 2011)

What is your cutback voltage set at? What is your cut off voltage set at? I can set both parameters. Setting the amperage cutback will begin cutting back your amperage at your predetermined voltage. The controller will not allow you to draw more amperage and will limit it as it sees needed. I had to set my cutback voltage lower so the car would not go into amp limit mode to early due to sagging cells under acceleration. I then set my cut off voltage to a limit just below that. So no matter what if I went below that it would cut off. I never got to shut down mode. But of the cutback mode you may have to set that lower to account for some sag. There is a limit so if your pack is set at 3 volts per cell you may want to set it for 2.8 or 2.7 volts per cell under load and sagging. I left mine after a few adjustments to 2.8 and it worked great. 

After that it would not allow my amperage to go above a specified percentage. That saves the cells from sagging too deeply. Cuts performance but you don't want to be hotrodding around near the end of charge anyway. 

What and how do you set those parameters? Do you have a link to the Zilla Manual? Or know where to find one. 

Pete


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## spdas (Nov 28, 2009)

I have the zilla manual and I think I got everything set right. Here are my settings.
a)BA, v)LBV, i)LBVI
600 119 124

a) Amp, v) Volt, i) RA
1000 154 500

r) RV, c) PA, p) PV
99 1275 143

l)Norm, r)Rev, x)Max
5000 1500 5200

a) On b) Off c) Off d) Off
e) On f) On g) Off h) Off
i) Off j) Off k) Off l) Off
m) Off n) On o) Off p) On

Errors, Old-New:
1111 1111 1111 1133 1141
State: 1312 Return for menu

EV-Fun has helped me with the settings and it seems to all be in order. But still the higher rpm performance sux....... like this...


0-2200 rpm I can get 670 motor amps 
from 2200 on up it tapers to 300amps 
and finally at 3300 rpm I can only get 200amps

francis


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## Guest (Sep 2, 2011)

I'd bump our motor amps to 800. It will cause your pack to sag more if running full out but it will give you more power for longer before tapering back. You will never be running full out at 800 amps anyway as your voltage is a limiting factor as well. 

Do you know what the zilla cuts the amperage back to when in cut back mode? I can change my cutback mode to any percentage of the max amps I wish. I set mine to 200 amps when in cut back mode. That way my controller will never allow more than 200 amps if I go below a voltage of 2.8 per cell even if it is under load sag. It allows me to have fun until my pack would begin sagging below that level. So no matter how hard I drive it won't allow more than that and help me keep my cells alive. I also have my low voltage setting which is very interesting too. If I set it to 2.8 volts it will no allow the controller to go below 2.8 volts period. If it needs to cut back amperage draw to keep the voltage at 2.8 it will so if I begin limping along at 30 mph I know none of my cells are below 2.8 volts per cell and my pack will remain safe. It is an interesting feature. Not just a current cut back but a voltage holder and will limit automatically the current to keep me at that level. 

I'd set your low voltage at like 3.0 volts per cell for fun and see if your controller limits the amperage to keep your cells at 3.0 even during sag. I am assuming it will. I never got my controller to actually shut off due to low voltage as the voltage limits would keep me just going slower and slower and slower but keeping the cells at that level. 


Your low voltage cut off where the controller would just shut off should be like 2.6 volts. No less. Cut back should be 2.8. And if correct you will never see 2.6 as your controller should adjust amperage to keep it at 2.8 until you can't move any longer. So when your controller starts current limiting you'r in limp mode. 

Now for your performance: 
What you show sounds pretty decent. If you lift your motor amp limit to 800 or 900 but below the limits of the controller then your performance will rise. I think you will be a happy camper with a bit more amperage. Your Zilla is designed to give you that. That is why it was made that way. Heck my Synkromotive will do that no trouble. Your Zilla should give better performance but you need amperage since your limited in voltage. 


Try a higher amperage setting like 700 at first. Then try 800. Report back.


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## spdas (Nov 28, 2009)

Thanks for the help, I know about the amperage cutout settings (BA) (LV) but some of the other settings you describe are not familiar to me. Maybe EV FUN can log in to see how it applies to my Zilla? thanks
francis


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## Guest (Sep 3, 2011)

Cut back voltage. The controller will limit the amperage to keep the voltage at or above the specified voltage limit so if you sag into that zone your controller will limit your amps. Put that voltage limit to something like 2.6 to keep from dropping into low voltage cutback too soon. It won't hurt your cells if you sag into that zone but if your at that voltage at a static setting then your at the very bottom for your cells. Your controller will lift the limits if you don't sag into that zone. That is what I was saying earlier. Put your amp max to 700 or 800 so you have more oomph when accelerating. You might even try 900 amps. It will sag a bit more at those amps so put your cut back limits to 2.6 per cell. What is your pack full charge voltage and how many cells?


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## Guest (Sep 3, 2011)

Do you have your vehicle in the garage here on the forum?


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## spdas (Nov 28, 2009)

gottdi said:


> Cut back voltage. The controller will limit the amperage to keep the voltage at or above the specified voltage limit so if you sag into that zone your controller will limit your amps. Put that voltage limit to something like 2.6 to keep from dropping into low voltage cutback too soon. It won't hurt your cells if you sag into that zone but if your at that voltage at a static setting then your at the very bottom for your cells. Your controller will lift the limits if you don't sag into that zone. That is what I was saying earlier. Put your amp max to 700 or 800 so you have more oomph when accelerating. You might even try 900 amps. It will sag a bit more at those amps so put your cut back limits to 2.6 per cell. What is your pack full charge voltage and how many cells?


45 cells @3.2 = 144v I have it set at 
Battery amps 700
Low Bat voltage 119 (2.64)
Motor Amp 1000
Motor volt 154 (it never has gone over 90v)

I can reach up to 670 battery amps but only to 2200rpm when it tapers off severely to 200amps @ 3300rpm.

francis


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## spdas (Nov 28, 2009)

gottdi said:


> Do you have your vehicle in the garage here on the forum?


I plead ignorance.... what is that. Will be back in a few as my 90# security system is hinting for a walk.


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## Guest (Sep 4, 2011)

Here you go: http://www.diyelectriccar.com/garage/

Post your information and photos here. You will see the link in the upper right. 

Nice security system. 

Mine is an almost perfectly round river rock the size of a soft ball. The latest in primitive security. Watch out it will do some serious damage. Cameras abound here as well. I can see you.


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## spdas (Nov 28, 2009)

Ok, I "applied" myself and posted to the garage last nite. Security is 95% about the appearance of force. We are about the only business here not broken into. I guess sooner or later we will have a stoned crack-head that has run out of copper street lighting wire to steal and think "nice puppy"... we will see. Keep your rock in a typical rock place (planter, etc.) to avoid the perp that does get his due from coming back and suing you attacking him with a dangerous weapon. 

I am down to 44 cells now. And still trying to figure out the controller.

francis


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## gojo (Feb 1, 2011)

Finding the most efficient motor speed would be a pretty easy experiment. Just try different gears in a trip one normally takes, and watch the ah's per mile for a while. 

Besides increasing range, I would like to know if higher RPM's would wear out the brushes faster for us DC guys, and without a tack, how does a person know when they are at 3500 rpm?

It would vary some from car to car, but maybe some people with tacks could tell us the speed at 3500rpm in different gears.

Right now I just leave it in 3rd in town, and start out in 2nd on the highway, and shift to 4th. I try to keep under 50, so I don't use 5th.


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## spdas (Nov 28, 2009)

gojo said:


> Finding the most efficient motor speed would be a pretty easy experiment. Just try different gears in a trip one normally takes, and watch the ah's per mile for a while.
> 
> Besides increasing range, I would like to know if higher RPM's would wear out the brushes faster for us DC guys, and without a tack, how does a person know when they are at 3500 rpm?
> 
> ...


I have not noticed a lot more efficiency driving at 3500 vs 2500, but in theory it should be. Maybe it will be more noticeable when I get my zilla sorted.

I start in 3rd as well and up to 50 if accelerating and if on a 40mph road I stay in 3rd and that is about 3000 rpm.
4th is about 3200 rpm at 55 and fifth is 2900 rpm at 60.

francis


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## Guest (Sep 5, 2011)

Why don't you use 2nd? You might find you get to speed faster.


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## spdas (Nov 28, 2009)

gottdi said:


> Why don't you use 2nd? You might find you get to speed faster.


In my case I start in third cause the controller is cutting back after 2300 rpm. In second i can reach 2300 rpm in a couple of seconds, so 3rd it is. Also I shift without a clutch (cause I use hand controls -I am in a wheelchair-) and shifting is really slow as it takes the motor a long time to rev down when going up to the next gear.

And for efficiency, I tried windows open vs windows closed and there was a measurable difference.

francis


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## Guest (Sep 5, 2011)

RPM limiter setting too low. Bump it up.


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## spdas (Nov 28, 2009)

gottdi said:


> RPM limiter setting too low. Bump it up.


it is at 5000 rpm already


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## Guest (Sep 5, 2011)

Sure your RPM Sending unit is set properly? I had one I used on the MG and it said I was doing twice as fast as I really was. My controller shut me down at 2500 real rpm but the controller thought I was at 5000. What RPM Sending Unit are you using?


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## spdas (Nov 28, 2009)

gottdi said:


> Sure your RPM Sending unit is set properly? I had one I used on the MG and it said I was doing twice as fast as I really was. My controller shut me down at 2500 real rpm but the controller thought I was at 5000. What RPM Sending Unit are you using?


The sender is the stock one for the warp. (not sure of the type). I tried freewheeling the motor and it max rpm's just as it is set to do. There are speed sensor 1 and speed sensor 2 and I think i tried both. I use zillaconfig for all my gauges
Wat u say above makes sense and I have been looking for a x2 or some such setting and there is none.

francis


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## Guest (Sep 5, 2011)

Setting the Zilla is out of my league. Sorry but something is surely causing a cutback too soon. Cooling working fine? If its not the Speed sensor issue something is causing a speed cutback. Guess it must be determined if its actually a Speed Sensor issue or not. Or connected properly and to the proper terminal or terminals. Anyway its beyond me. My controller is much simpler. 

Pete 

I will be watching to learn more myself. Good to know and learn troubleshooting issues.


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## spdas (Nov 28, 2009)

Aloha Pete, thanks for your help.
Not a heat issue as motor runs 65c and my water cooling is working.
I tried every setting up to 1000amp battery and 10,000 rpm and nothing

*****BUT**** I got an error. 1224 : SLI battery too low and caused shutdown of controller. 
What is SLI? Starting, Lighting, and Ignition battery, a battery designed for use in a conventional gasoline automobile. My aux battery is at 12.8v 


HMMM this car used to run SLA's [email protected] 12.6 (avg) 176.4 v. Now I am at 140 or so V. Is there a memory somewhere?

francis


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## Guest (Sep 5, 2011)

I was thinking that the controller might be getting hot but now that you mention SLA cells you might still have some parameters set that were from the old setup. Sounds very plausible. See, your closing in on what just might be the real issue. Your car may be set up properly but the computer is not set correctly. I'll go look at that manual again. 


Pete


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## spdas (Nov 28, 2009)

Aloha, Pete. I continued the zilla problem on a new thread called zilla error. I think I may, just may, be getting somewhere.

francis


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## spdas (Nov 28, 2009)

Well, I am down to 44 cells. (2 bite the dust) and I think the final 3 of the troublesome 5 will hold, but I am ordering a replacement 5 to bring my voltage up anyway.

Seems the cells are getting stronger-----normal? As every time I go over the hill and travel 72.7 miles I use less AH, even now with one less battery and today with strong headwinds going up the 4 mile hill. Drove 55-60 mostly and used 13800kw according to the zilla readout.

I average 190 watts per mile. I think I can get it below 170wpm if I get rid of the wide tires, and put an underskin.

What is a bit weird is that the other week when i went 100 miles, I got 186w-mile and was going considerably slower averaging maybe 40-45mph. Not a big difference as I would have expected when going 55-60, @190wpm.

francis


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## Guest (Sep 12, 2011)

I think your doing real good. You might consider the low rolling resistance tires. They seem to be the best bang for the buck. Yes less on the road. You may not be actually getting better performance from the batteries but from your driving style. I have found that after some time behind the wheel my driving style has actually changed. That changed the Watt Hours per mile I can do. I am getting around 3.8 to 4.2 miles per KWH in the Leaf.


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## spdas (Nov 28, 2009)

"That changed the Watt Hours per mile I can do. I am getting around 3.8 to 4.2 miles per KWH in the Leaf."

Is it not watts per mile and 3.8 miles per KW? Shoot.... you better not be right, i thot I had it figured out!

Francis


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## Guest (Sep 12, 2011)

The Leaf calculates at Miles per KWH. 

Pete


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