Imiev efficiency on the highway

[DonDakin]

I recently watched this video

http://youtu.be/ubDItYYrtZ0

And i thought i would try this on the imiev for comparison sake.

I did 4 runs on a 7km mile stretch of the highway 2 at 80 km per hour and 2 at 110 km per hour. I did the runs in both direction to compensate for wind and elevation differences.

Results were 110/124 wh/km at 80 km per hour and 156/189 wh/km at 110 kph.
That gives an average of 117 wh/km at 80 kph and 172.5 wh/km at 110 kph.

So in the imiev driving at 110 kph vs 80 kph takes 47% more energy.

It was also interesting to note that at 80 km per hour the wind/elevation made a 13 % change vs at 111kph the difference was 21%.

Also interesting is that comparing with bjorns numbers for the leaf the imiev is 16 % more efficient at 80 kph and 13% more efficient at 110 kph.

I did this test with canion and included in the test is the acceleration from 65 kph on the freeway entrance on ramp. I mean i reset canion just as i was getting on the freeway.

Most of us already know this qualitatively but i thought it was nice to have some numbers.

One other interesting thing is the imiev speedo seems to be about 2.5 kmph slow compared to the gps. I guess mitsu did that to help out just a little bit more on the range of the car.

Don.....

 

[mdbuilder]

80 kph is so damn slow :lol:

 

[Don]

80 kph is so damn slow :lol:

That's 50 mph - I'm at that number or below for about 95% of my driving. Probably why I regularly see middle 80's on the RR gauge after a full recharge . . . . and I can actually go 80 miles on a charge most times :mrgreen:

Don

 

[wmcbrine]

One other interesting thing is the imiev speedo seems to be about 2.5 kmph slow compared to the gps.

Are you saying that it would read 80 on the speedometer, and 82.5 on the GPS? Or the other way around?

 

[DonDakin]

80 on the speedo was 77-78 on the gps. In kph.

Don....

 

[Don]

80 on the speedo was 77-78 on the gps. In kph.

Most cars I've driven have speedo's that read a bit higher than the actual speed. I think the manufacturers do that on purpose. It does reduce the likelihood of you getting a speeding ticket

Don

 

[PV1]

Both of my cars are the opposite. Roadside radar signs and GPS register 1 MPH higher than the dash speedometer...except when I had the 175/55R15 tires on the back, then it was 3 MPH higher than actual (but no regen).

 

[JoeS]

...Most of us already know this qualitatively but i thought it was nice to have some numbers...

DonDakin, thanks for posting. In the same vein, if anyone is interested in seeing the theoretical curves of range vs. speed, here's the link:
http://myimiev.com/forum/viewtopic.php?p=17565#p17565

 

[mdbuilder]

80 kph is so damn slow :lol:

That's 50 mph - I'm at that number or below for about 95% of my driving. Probably why I regularly see middle 80's on the RR gauge after a full recharge . . . . and I can actually go 80 miles on a charge most times :mrgreen:

Don

Last night after a few trips over the weekend I was down to 15 miles on the RR with the A/C on. I washed it and decided to blow off the water on the local loop past the Starbucks which is appr. 12 or 13 miles.

First 5 or so miles a/c on, 45-50 following traffic. At the turn I was getting slightly concerned so I killed the a/c and continued at normal if somewhat slow speed to Starbucks. Leaving there with 10 miles on the meter and 7 miles to go I did the first couple down the highway at 45 max, no traffic ahead. Then I got behind two trucks loaded with pavement for the nights work. Followed them for almost 3 miles at 25-30, followed by a slight and short climb at 40mph and the downhill glide to my house for the last .75 miles.

This morning there is 86 miles on my RR meter. 11 miles more than the previous high and 19 miles more than my most common normal reading. If I had to drive like that all the time I might need to shoot myself :shock:

 

[Don]

I guess it depends on where you live and where you drive

We live in the country on a 40 mph road and other than a very brief stint on the freeway to get across the bay (4 miles) our car never sees a road with a speed limit above 45, so going slowly, getting a great range is as simple as just flowing with the traffic - We're no slower than anyone else and we're definitely not holding up traffic. IMO, this is the sort of use the car was designed for - They would have given it a much better co-efficient of drag if they thought it was going to be used as anything other than an urban commuter car

If we needed a freeway car, we'd own a Tesla!

Don

 

[mdbuilder]

When Tesla's are <$20K used I'll consider it.

I'm perfectly fine with the I-Miev for my commute at 50-60 mph and 20 - 25 miles per day, works out well.

For longer actual high speed travel I have a gas powered NV-200 to carry my toys. It blows down the highway @ 80-85 mph effortlessly and climbs 6 and 7% grades like a locomotive <g>. The CVT lets the motor wind up as the grade gets steeper. 7% grade and 85 mph corresponds with the hp peak @ 5,200 rpm :twisted:

 

[FrostyCanada]

One other interesting thing is the imiev speedo seems to be about 2.5 kmph slow compared to the gps. I guess mitsu did that to help out just a little bit more on the range of the car.

Hello Don, we noticed the same thing with our little imiev, but the speedo was actually faster.

Our town put up radar signs showing the posted speed limit and your actual speed.

The imiev speedo registered a difference of about 2-3 km faster as compared to the electronic radar signs.

Brian

 

[DonDakin]

Well now I'm curious.

My GPS says the Speedo in the car is slow 2-3 KPH.

Frosty's radar sign says it's fast..... (maybe that offset the radar to get people to slow down ?)

Anybody else want to test with a GPS and chime in ?

Thanks

DOn.....

 

[FrostyCanada]

Hello Don, I'll test both again ....

I'll report back tonight,
Brian

 

[JoeS]

This morning there is 86 miles on my RR meter. 11 miles more than the previous high and 19 miles more than my most common normal reading.

See, you were rewarded for your efficient driving skills!

Last night after a few trips over the weekend I was down to 15 miles on the RR with the A/C on. I washed it and decided to blow off the water on the local loop past the Starbucks which is appr. 12 or 13 miles.

Why in the world would you even start off on a trip like this, as there was nothing pressing? You were guaranteed to be down to one bar blinking before you even left home!

If I had to drive like that all the time I might need to shoot myself :shock:

Nah - lesson learned: plan ahead. If you had it plugged in while you were washing the car, you'd have been ok. :shock:

 

[mdbuilder]

Eh, it is just a number on a gauge which is meaningless for real world driving, not some "reward". The next day it started @ 86 and was down to 61 7.1 miles later arriving at work.

 

[JoeS]

Eh, it is just a number on a gauge which is meaningless for real world driving, not some "reward". The next day it started @ 86 and was down to 61 7.1 miles later arriving at work.

At 80mph?

I'm afraid I must disagree with you regarding real-world driving applicability of the RR gauge: We know ahead of time that the number is a moving average of the preceding 15-miles. Knowing that, we also can now mentally compensate for speed, elevation changes, and windspeed. As the fuel gauge goes down, I find myself relying on the RR gauge equally with the fuel gauge - especially on longer trips where I bounce RR against the GPS DTG (Distance To Go). If DTG>RR, I pay attention and take early corrective action.

 

[mdbuilder]

No, not 80

45-60 is the speed range on my commute, mostly 50-60.

I knew exactly why it was 86 and that it was totally meaningless. It's not that the meter is meaningless, just that particular value. Most days with 25-30 miles of driving I don't need the RR meter and don't pay too much attention to it.

If I have>40 miles to drive I do use it just as you say. Although my goal is to at least keep up with traffic and blast the A/C as much as possible this time of year. Unless the trip is > 60 then I go in to full economy mode but still, there is a limit to how slow you can go on these rural roads without getting run over by a good old boy in a pickup. Speed limits are generally 50 mph but are considered somewhat optional

 

[PV1]

...but still, there is a limit to how slow you can go on these rural roads without getting run over by a good old boy in a pickup. Speed limits are generally 50 mph but are considered somewhat optional

Amen to that! Hard to stretch the range with someone's grill taking up your entire rear view mirror because 10 MPH over the limit isn't enough for them. On the other hand, maybe I'll make a hitch-mount push bar so that I can put the car in Neutral and they can push me along :mrgreen: :roll: .

 

[sandange]

Just did a Speedometer to GPS reading check...
The Miev is fitted with original tires worn just over 1/2 way

80 km/hr on the speedometer reading was 77 km/hr on the Garmin
110 km/hr on the speedometer reading was 105 km/hr on the Garmin

49.7 mph on the speedometer reading was 47.85 mph on the Garmin
68.35 mph on the speedometer reading was 65.24 mph on the Garmin