Speedometer off?

[jmeitz]

So this is something i should have paid attention to 10k miles ago. Driving down the highway today had cruise set on 70 and i look over at the car next to me which is a new accord. the speed readout shows 65 and we are side by side. So i find another vehicle with a digital read out and theirs is 64. So a few miles up a lexus passes me and theirs is set on 70 and just goes right by. So apparently my leaf is off by 7-8%, so i assume my mileage is off as well which concerns me as this is a lease and i would be paying for miles that are not being used. Would the dealer be able to fix this issue or would they simply say all the other cars are off?

 

[Den]

Measuring by another cars is bad idea. Find a road radar with display and measure by this. Mine is only 3km higher than radars shows. Also GPS is good to check.

 

[TomT]

In the old mechanical days, that may have been true as the odometer and speedometer were essentially tied to each other from the same mechanical input. But in these electronic days, the speedometer can be fast (on purpose, usually), while the Odometer is dead on since they are two completely different devices... Still, your error seems excessive... Do you have the stock tires on the car? Best bet is to run a measured mile and check both for accuracy.

 

[dhanson865]

from http://www.mynissanleaf.com/viewtopic.php?p=318782#p318782" onclick="window.open(this.href);return false;

You can correct this by buying different tires when the time comes.

Stock P205/55R16 837 24.9" can be switched for P205/60R16 810 25.7" Michelin Energy Saver A/S which will lower the speedometer by about 3-4%. I think that would be about the best adjustment you could make (and you get a better LRR tire in the process if you switch from the Ecopia EP 422 to the Energy Saver A/S).

Stock P215/50R17 815 25.5" is likely OK already, I wouldn't recommend going up to the 225/50/17 as it will likely reduce your range and may make the speedometer too slow.

after reading viewtopic.php?f=31&t=13776&start=50#p318678 I'm adjusting the desired RPM / diameter for accuracy at highway speeds to about 805 RPM and overall diameter of about 25.9" but in most tire lines you won't find an exact match to that target so I'd choose very slightly higher RPM / lower diameter over the opposite making the soft targets to be 805 to 815 rpm or said another way between 25.9" and 25.5" overall diameter.

Tires to consider in 16 and 17" are

Michelin Energy Saver A/S
P205/60R16 91V SL Green X 480 A A 51 psi max 21 lbs. 25.7" 810 US
215/50R17 90V SL Green X 480 A A 44 psi max 22 lbs. 25.5" 815 CA

Yokohama AVID Ascend
P205/60R16 91H SL BluEarth 740 A A 51 psi max 22 lbs. 25.7" 808 US
P215/50R17 93V XL BluEarth 740 A A 50 psi max 26 lbs. 25.5" 814 US (heavier than most here)

Continental PureContact with Ecoplus
205/60R16 92H SL EcoPlus 700 A A 51 psi max 21 lbs. 25.7" 808 MX
215/50R17 95V XL EcoPlus 700 A A 51 psi max 22 lbs. 25.5" 815 MX

Bridgestone Turanza Serenity Plus
205/60R16 92V SL LRR 600 A A 51 psi max 24 lbs. 25.7" 812 TH (also on the heavy side)
225/50R17 94W SL LRR 500 AA A 51 psi max 25 lbs. 25.9" 804 ID (also on the heavy side, and wider than the others here)

all of these tires are rated well by tirerack customers though you will see differing efficiency (miles/KWh) with the Energy Saver A/S presumably giving you the most miles per charge.

The heavier tires tend to handle higher loads if you like to move heavy objects in your leaf but they also tend to waste more energy, the wasted energy is a small factor but one some would consider.

Wider tires tend to trade wasted energy for a more stable ride (think cornering). Width is a more noticeable factor than weight when it comes to range/efficiency.

I'd love to see side by side or back to back tests of any of these tires on a Leaf, for now all I'm doing is data diving.

 

[todatsu]

Hello to the gang, I have a question about the speedometer inaccuracy:

After doing at least fifty "opportunity" radar checks at a total of about ten different radar locations, well over half the radar checks agree and they all say my speedo reads 5% high (reading 63mph for 60mph et cetera) at road angles near 0 degrees. Very repeatable. The LEAF has the "small style" 16 inch wheels.

I want the speedo to be right so other cars aren't constantly tailgating me as they often do now, it is unsafe for all. And if I do choose to exceed the speed limit for any reason, I want to know by exactly how much. Unfortunately the speedo adjustment screen only allows +/- 2% correction.

Here is a question: When I open the adjustment screen, do I change it to the minus side or the plus side? I have searched the forum but can not find this info.

Thank you in advance for your reply !

 

[jmeitz]

Measuring by another cars is bad idea. Find a road radar with display and measure by this. Mine is only 3km higher than radars shows. Also GPS is good to check.

GPS shows at 70 its off by 5-6 mph and at 40 its off by 3.

 

[garygid]

Speedometers are required to NOT indicate LOW with
standard equipment. So, most vehicles (at least non-
commercial vehicles) display about 1.5% higher than
the speed that the car actually thinks that it is moving.

Adding air to the tires is the easiest partial fix.

Is there speedometer error adjustment in the 2013 models?

Do we have adjustment in the 2011 and 2012 models?

Thanks, Gary

 

[todatsu]

Is there speedometer error adjustment in the 2013 models?

Hello Gary, nice to meet you!

Yes there is, but the adjustment screen does not include a tip such as "if speedometer reads high, utilize the minus button"

So I pegged it at 2% low. It is going to take weeks to verify a change, even in which direction! Meanwhile I no longer have any idea what speed I am going. Thanks, Nissan.

Regarding adding more air, my false belief was if I ran my Nissan Cube tires at maximum inflation it would give me better gas mileage. 25,000 miles later all it did was wear out the center tread. Not wanting to spend another $700 for more new tires, I underinflated them to wear out the side tread. Surprise! Numerous calculations showed the gas mileage was essentially the same, under- or over-inflated.

I'm at 36 psi currently in the LEAF

 

[garygid]

Compare the speedometer to the GPS speed on flat land.
If you can do that, then one drive is enough to adjust
the indicated-speed correction factor, if that is really what
the adjustment does.

The 2011 has a hidden Diagnostic screen, entered with car On
and Audio system Off: press MAP, MAP, MAP, Audio Power (On),
Audio Power (Off), and finally MAP (once) again. 3, 2, 1.
About 3 presses per second, approximately.
(Or, am I thinking of the 2010 Prius?)

Is that available in the 2013 models?

Looking at the GPS data, there is a speed-related figure that
is 1000 (100.0 kph) at about 62.5 mph. 80 kph (800 indicated)
would be 50 mph, and your car would usually indicate about
51 mph on the speedometer.

I think that the latest version of the Android LEAF Spy app
can show the car's internal "speed".

Tire Pressure does make a substantial difference in range
in a carefully-driven LEAF.

Also, some/many LEAF tires are wearing on the edges,
when inflated to "factory spec" pressures.

An ICE is rarely ever driven "carefully", and the engine
wastes so much energy, that tire pressures might
not have such an obvious effect.

But, YMMV

 

[dhanson865]

Regarding adding more air, my false belief was if I ran my Nissan Cube tires at maximum inflation it would give me better gas mileage. 25,000 miles later all it did was wear out the center tread.

You'll find if you do enough research that drivers of Hybrid and Electric vehicles are having to run higher and higher PSI to keep tread wear even.

Prius, Leaf, Tesla pick one and read the forums and you'll find users that had uneven wear at pressures they thought were OK. Then they tried a higher pressure and found the car handled better and the tires wore more evenly.

As to the Leaf vs Cube the weights are

Leaf 2011/12 models
1,521 kg (3,354 lb)
2013 model
1,493 kg (3,291 lb)

Cube
1200 kg, 2646 lb

The more the car weighs the higher the PSIs you'll need, The Cube just doesn't weigh as much as the Leaf.

 

[Wennfred]

Just took the Leaf out for a spin late tonight. Last week, while using the Speed Box App and a Garmin GPS, I was running 3 to 4 MPH faster on the dash display then what was reading on both the Speed Box app and the Garmin. So tonight, I entered the Nav setting section and adjusted the Speed Calibration to -1.5 at first and still had like 2 MPH separation, I kept adjusting down to -2 with really no change and then to the full -2.5 offset and was able to get with in 1 MPH. On a flat strip along the ocean on Silver Strand, I set the cruise control to 55 MPH and both the Speed Box App and Garmin GPS stayed locked in at 54 MPH. It didnt matter what speed, whether it was 30, It would read 29 on the GPS. Took it up to 65 and both GPS read 64. Tire PSI Set at 44 on Stock Ecopia tires. Im hoping that this coming Friday when I get my 4 new Nokian Entyre tires the reading will match, if not I can live with 1 MPH off. Will see, more to follow.



Fred

 

[cwerdna]

This has been discussed numerous times. http://www.mynissanleaf.com/viewtopic.php?f=8&t=8026" onclick="window.open(this.href);return false; is an example of a previous thread on this.

 

[todatsu]

This has been discussed numerous times. http://www.mynissanleaf.com/viewtopic.php?f=8&t=8026" onclick="window.open(this.href);return false; is an example of a previous thread on this.

Yes you are right, I planned to post in the big thread, then this one appeared.

To Gary -- Yes I am using the 2013 diagnostic screen explained by the good members here.

Many thanks guys for filling in the missing pieces of info! Those GPS numbers were all Greek to me but now it should be easy to find which one is speed. I appreciate the heads-up to keep an eye on the tread wear. It really is quite a nice car except for a few software glitches.

Forgot to mention both my Cube and also the Rogue speedometers were right on, -0 / +1. That spoiled me I guess.

Thanks for the tire chart that will come in handy some day!

 

[cwerdna]

^^^
That's not a "big" thread. http://www.mynissanleaf.com/viewtopic.php?f=30&t=8802" onclick="window.open(this.href);return false; is a BIG thread w/6510 replies taking 652 pages.

 

[garygid]

If you have an Android device with GPS (like the Kyocera Event),
the "GPS Test" app seems to be very good. It is free at
the Google Play Store, in the apps section.

I use it, and it has some very nicely done displays,
including a Speedometer screen, global location with
sunshine zone, a map of the satellite positions in
your local sky, time clocks, and satellite data and
signal strengths. All quite well done, it seems to me.