distance estimator higher than distance actually covered

Hi all,

A quick search didn't find a thread on this topic, but if there is one, please point me to it.

I'm a fairly new Leaf owner, although I am already on my second one. About a month ago, I bought a 2013 S. When I bought it, it had 10 bars, but a few days ago it dropped to 9. It could go about 110km on a full charge on my freeway test, maintaining about 90km/hr.

In case anyone is not conversant with metric, and if I correctly recall Canada's pre-metric days, 90km/hr is approx. 55mph, and 1 km is approx .6 mile (or 1 mile is 1.6 km).

Two days ago, I traded it for a 2016 SV because I wanted longer range, cruise control, 12 bars of battery and the option of fast charging. The SV has all of those, and the salesguy estimated it would go about 175km on a full charge.

I took it out for a bit of a range test yesterday. I was on a relatively flat freeway with no wind and little traffic. My winter tires are 205 50R16 instead of the stock 215 50R17, so I have calculated my speed and distance taking into account the approximate 5.5% smaller circumference. I set cruise control at 95km/hr (approx 90 actual)

At the start of the first leg, the battery showed 83%, the "distance estimator" (that's what I'll call it) estimated that I could go 148km. After 57km, the estimator estimated I could go another 65km. In other words, the estimate dropped 83km in the 57km I travelled.

I quick charged to 91%, which now estimated I could go 154km. I travelled 114km, and the estimator said I could go a further 14km. In other words, the estimate dropped 140km in the 114km I travelled.

I have now charged to 100% and the estimator says that I will be able to go 162km. By extrapolating my results from yesterday, I think it will only go about 135km, or approx 83% of what it estimates. While any of my calculations may be slightly in error, I think it's clear that it's a significant overestimation.

I assume that the smaller tire size would not account for this, because although the wheel has to spin faster to obtain a given speed, is should be less stress on the motor to turn it. If I am wrong and this is the problem, please advise.

I read that there was a concern of rapid degradation of the 30Kw battery packs, but that Nissan said it was a software bug that caused the vehicle to think it had less range than it actually had, and that it could be fixed with a software update. Could this be related to that problem?

Thanks

You don't necessarily have rapid degradation. The range estimator is nicknamed the "Guess O Meter" by Leaf drivers. It takes the last few minutes of driving efficiency, and uses that - and that only - to estimate range. So if you drive slowly right before parking the car (as most do!), you will start with a wildly optimistic range estimate that slowly corrects itself over the course of your trip.It is usually accurate right at the end. ;-) The SV and SL have a second, better estimator, but not the S, I'm afraid.

Well, the guess o meter on the S (which I only had for a month) was pretty darn stable and accurate.

Maybe a more succinct and better question is:

On a 2016 SV with 30kw battery pack at 12 bars, is a range of 135km (85 miles) about all I can expect on a full charge?

It's hardly an improvement on the 2013 S with 24kw battery pack at 9 bars that got 111km (70 miles).

w35t0b said:

Well, the guess o meter on the S (which I only had for a month) was pretty darn stable and accurate.
Maybe a more succinct and better question is:
On a 2016 SV with 30kw battery pack at 12 bars, is a range of 135km (85 miles) about all I can expect on a full charge?
It's hardly an improvement on the 2013 S with 24kw battery pack at 9 bars that got 111km (70 miles).

Click to expand...

If the weather has changed in you area (winter ?) you are comparing apples to oranges in so far as your energy consumption per mile goes.

A 30 kWh LEAF at 12 bars has at least 28*0.85 = 24 kWh of usable energy from full to empty
A 24 kWh LEAF at 9 bars has about 22*0.73 = 16 kWh of usable energy from full to empty.

So *all else being equal,* your newer car has 50% more range. Put another way, I doubt you would still be getting 110 Km in your older LEAF today. Maybe when it warms up again ;-)

Check out the threads discussing ways to improve EV range in the winter. They mostly come down to avoiding cabin heating and using the wheel and heat seating instead. As a side benefit your GOM accuracy will improve since you will not be using a lot more heat at the start of the drive compared to the end.

Since I only had the S for about 4 weeks, the weather has been similar for tests on both cars, about 45-50F or 7-10C.

I have a 2017 S and the GOM will show anywhere from 110 to 135 miles based on how I was driving just prior to charging to 100%.

Forget the GOM - it’s not going to give you an accurate range estimate.

You should get LeafSpy to better understand the true state of your battery. Lacking that, you’re better off developing your own range chart using SOC% vs distance traveled - at least SOC% is more accurate than the GOM.

And to your original question - a 12 bar 30 Kwhr Leaf should give you 100-110 highway miles / 160-180 km depending on your speed.

w35t0b said:

On a 2016 SV with 30kw
...
2013 S with 24kw battery pack a

Click to expand...

Battery capacity is measured in kWh, not "kw".

It is a complete waste of time to discuss the GOM. Tony's right with his post: http://www.mynissanleaf.com/viewtopic.php?p=271853#p271853.

For unit conversions, Google makes a great unit converter for the units we use here. Google for these, for example:
90 kmh in mph
100 km in miles

Has anyone calculated reduction of range concordant with reduction of ambient (outside air) temperature?

Tony Williams came up with some rules of thumb at http://www.mynissanleaf.com/viewtopic.php?t=4295.

Also, when you give/measure speeds and distances, have you confirmed them w/GPS or something else? There already is some speedometer error (speedometer reads higher than actual) even w/stock tires.

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=177 also points out differences between worn and new tires.

When the GPS indicated exactly 100 miles had been traveled while the vehicle was equipped with new 12/32" deep tires, the vehicle's odometer registered 99.4 miles. When the vehicle was then equipped with another set of the same tires shaved to 2/32" of remaining tread depth, the odometer indicated 101.0 miles. While the 100-mile test distance didn't change, essentially the vehicle's odometer overstated the distance traveled by about 1.5% when equipped with the worn out tires.
...
As shown above, there are slight differences between the tires' published diameters, tread depths and tire revolutions per mile. However, if a tire rolls fewer times per mile than the tire it replaces, the vehicle will again actually be traveling farther than is indicated by the odometer. Calculating the influence of the different tire specifications on the vehicle's odometer would indicate the Yokohama AVID TRZ would travel .6% farther than the Goodyear Integrity, while the General Altimax RT would travel 1.4% farther.

Click to expand...

Again, there's no point wasting time w/the GOM.

Look instead at roughly how many kWh you have available and efficiency (in miles/kWh or km/kWh). This is analogous to gallons and miles per gallon... err... litres and km per litre.

If you want to go further, you need to improve your efficiency (miles/kWh or km/kWh) which you can do by slowing down, turning off the heater and AC, inflating your tires to a higher pressure, using tires w/lower rolling resistance, etc. Preheating on shore power can also help.

w35t0b said:

Has anyone calculated reduction of range concordant with reduction of ambient (outside air) temperature?

Click to expand...

You'd also have to factor in the altitude, so it would get pretty time-wasting.

OK, I think I get it now.

Thanks everyone.

There is only about 800 meters in a Nissan Kilometer. Kilo = 800